FIELD OF THE INVENTION

In the first place, the invention relates to a system that is designed to realize an anti-biofouling effect on a marine object such as a drive unit for use with a vessel, the system including at least one light source that is configured to emit anti-biofouling light.

In the second place, the invention relates to an assembly of a system as mentioned and a marine object as mentioned.

BACKGROUND OF THE INVENTION

Various structures that are temporarily or permanently exposed to an aqueous environment are prone to biofouling. For instance, in a marine environment (including both seawater and freshwater), marine objects such as vessels, oil rigs, pipelines, support structures for sea-based wind turbines, structures for harvesting tidal/wave energy, etc. are subject to organisms growing on them, especially in areas that are temporarily or

permanently exposed to water. As a result, the drag of vessels increases, the moving of parts can be hampered, and filters can become clogged. In respect of the influence of biofouling on the drag of vessels, it is noted that biofouling can involve an increase of up to 40% in fuel consumption. For the sake of clarity, it is noted that the word“vessel” as used in the present text is to be understood as referring to a watercraft such as a ship, a boat, a yacht or a submarine.

In general, biofouling is the accumulation of microorganisms, plants, algae, small animals and the like on surfaces. According to some estimates, over 1,800 species comprising over 4,000 organisms are responsible for biofouling. Hence, biofouling is caused by a wide variety of organisms, and involves much more than an attachment of barnacles and seaweeds to surfaces. Biofouling is divided into micro fouling that includes biofilm formation and bacterial adhesion, and macro fouling that includes the attachment of larger organisms. Due to the distinct chemistry and biology that determine what prevents them from settling, organisms are also classified as being hard or soft. Hard fouling organisms include calcareous organisms such as barnacles, encrusting bryozoans, mollusks, polychaetes and other tube worms, and zebra mussels. Soft fouling organisms include non-calcareous organisms such as seaweed, hydroids, algae and biofilm“slime”. Together, these organisms form a fouling community.

As mentioned in the foregoing, biofouling creates substantial problems.

Various methods have been developed to address these problems. For instance, robots exist that are designed to scrape biofouling from the hulls of vessels. Another method involves irradiating a surface that is subject to biofouling with anti-biofouling light. In this respect, it is noted that ultraviolet light, particularly ultraviolet light of type C, i.e. UV-C light, is known for being effective when it comes to anti-biofouling so that good results may be achieved.

It is an object of the invention to provide ways of effectively applying the method according to which anti-biofouling light is applied in order to obtain a satisfactory level of anti-biofouling results even if a marine object is of a relatively complex structure.

SUMMARY OF THE INVENTION

The invention provides a system that is designed to realize an anti-biofouling effect on a drive unit for use with a vessel, the system including at least one light source that is configured to emit anti-biofouling light, and the system being arrangeable with respect to at least a part of the drive unit that is intended to extend from the vessel at an outside of the vessel, for emitting the anti-biofouling light towards, in and/or away from the drive unit in an activated state of the system.

Basically, a drive unit for use with a vessel comprises components for providing the vessel with thrust and a motor for driving the components. The components for providing the vessel with thrust may comprise at least one propeller arrangement that is to be located outside of the vessel. The motor may be accommodated in a housing that is intended to be located outside of the vessel as well, but it is also possible for the motor to be intended for placement in the vessel’s interior. Besides the components directly involved in thrusting the vessel and the motor for driving those components, a drive unit for use with a vessel may comprise many other components such as components designed to realize a steering action on the vessel by means of the drive unit. Generally speaking, as compared to the relatively smooth appearance of the vessel’s hull, a drive unit for use with a vessel is of a complex design and includes numerous areas that are both prone to biofouling and hard to reach. Practical examples of a drive unit for use with a vessel include stem drives and azimuth thrusters.

An anti-biofouling system is provided that is designed to realize an anti- biofouling effect on a drive unit for use with a vessel, the system comprising a receiver for comprising at least one light source that is configured to emit anti-biofouling light, and the system being arrangeable with respect to at least a part of the drive unit that is intended to extend from the vessel at an outside of the vessel, for emitting the anti-biofouling light towards, in and/or away from the drive unit in an activated state of the system. The receiver may comprise a light source socket, a clamp for holding a light source, a volume for receiving a light source, etc.

An anti-biofouling system is provided that includes at least one anti-biofouling light source and that is arrangeable with respect to at least a part of the drive unit that is intended to extend from the vessel at an outside of the vessel, i.e. at least a part of the drive unit that is exposed to water during a major part of its lifetime, for emitting the anti- biofouling light towards, in and/or away from the drive unit in an activated state of the system. Hence, the invention covers various options of achieving an anti-biofouling effect on a drive unit despite the relatively complex design of such a type of marine object. The system according to the invention may be provided as one or more units that are to be arranged in, on, or at a distance from the drive unit, wherein it may or may not be advantageous for the design of the drive unit to be adapted for the purpose of enhancing anti-biofouling effects, for example by making one or more parts of the drive unit transparent to the anti-biofouling light. A practical way of arranging the system at a distance from the drive unit may involve arranging the system on the vessel. In general, the system may include at least one carrier that is arrangeable to extend from the vessel at an outside of the vessel, from the drive unit and/or in the drive unit. Further, the system according to the invention may be realized as an integral part of the drive unit, for example by designing the drive unit with one or more transparent parts in which discrete light sources such as UV-C LEDs are embedded.

It follows from the foregoing that practical ways of making the system according to the invention available involve providing the system i) as a part, probably an integral part, of the drive unit, ii) as an add-on of the drive unit and/or the vessel on which the drive unit is to be used, and iii) on a separate carrier. Emission of anti-biofouling light in a direction away from the drive unit may be achieved by arranging a suitable kind of light- emitting covering on the drive unit.

In the following, particulars of a number of practical embodiments of the system according to the invention are defined and explained, wherein it is to be noted that those embodiments are not only applicable to a drive unit for use with a vessel, but also to a marine object in a more general sense, and wherein it is to be noted that it is possible to have combinations of the various possibilities. In the first place, the system may include at least one movable component that is configured to be movably arranged on the vessel, on the drive unit and/or in the drive unit. The at least one light source of the system may or may not be arranged on the at least one movable component. One possibility for the at least one movable component is to be arranged so as to cover the at least one light source of the system in one position and to allow exposure of the at least one light source of the system in another position. Another possibility for the at least one movable component is to serve as a carrier of the at least one light source of the system, so that the at least one light source can be moved to various positions by means of the movable component, including at least one position in which the at least one light source may be effective in having an anti-biofouling influence on the drive unit. In a practical embodiment, the system may include at least one hinge element, and the at least one movable component may be configured to be hingeably arranged on the vessel, on the drive unit and/or in the drive unit through the at least one hinge. The hinge element may comprise a linear hinge or a ball hinge, for example. The at least one movable component may be of any possible design, wherein it is noted that it may be practical for the at least one movable component to be shaped like some kind of sheet/panel.

In the second place, the system may include a deployable arrangement that is movable between an activated position associated with the activated state of the system and an inactivated position. In this respect, it is noted that the deployable arrangement may comprise at least one of a telescopic arrangement, a foldable arrangement, and an inflatable arrangement. For example, the system may include something like an inflatable bag that that is provided with one or more anti-biofouling light sources, and that is arranged and dimensioned so as to encompass at least a part of the drive unit that is intended to extend from the vessel at an outside of the vessel, i.e. at least an exterior part of the drive unit, when the drive unit is not in operation. In such a case, the one or more anti-biofouling light sources may be arranged in/on the bag’s material and comprise UV-C LEDs or the like, which does not alter the fact that it is also possible for one or more anti-biofouling light sources to be arranged in the interior of the bag in inflated condition. According to another possibility, the system may include a foldable awning-like device that can be pulled up or pulled out to face/encompass at least a part of the drive unit that is intended to extend from the vessel at an outside of the vessel, wherein it may be practical for the one or more anti-biofouling light sources to have a position in/on the device’s material besides other optional positions.

In the third place, the system may include at least one fixed component that is configured to be fixedly arranged on the vessel, on the drive unit and/or in the drive unit. For example, the system may include a kind of sleeve-like element for carrying one or more anti- biofouling light sources and/or serving as a light guide for anti-biofouling light and/or one or more light-emitting fibers, which sleeve-like element and/or one or more light-emitting fibers may be arranged so as to encompass a part of the drive unit. Another possibility involves the system being configured to be fixedly arranged on the drive unit and/or in the drive unit and to emit the anti-biofouling light away from the drive unit. In this respect, it is noted that the system may comprise tile-like units that can be actuated to emit anti-biofouling light and that can be arranged on one or more surface areas of at least the exterior part of the drive unit.

In the fourth place, when the system is particularly designed to realize an anti- biofouling effect on a drive unit that is movable between an operable position and a stowed position, the system may include a housing for accommodating at least a part of the drive unit in the stowed position thereof. The at least one light source of the system may be realized as a plurality of UV-C LEDs arranged on an interior surface of the housing, for example, which UV-C LEDs may emit anti-biofouling light directly towards the drive unit in the stowed position in that case.

It may be practical for the system according to the invention to comprise a net- shaped structure that may be fixedly arranged so as to cover or encompass at least a part of the marine object, or that may be movable between a position for emitting anti-biofouling light towards and/or from the at least a part of the marine object, and another position. Such a net-shaped structure may be made up of a number of light-emitting fibers, for example.

Alternatively, some kind of blanket structure or other structure suitable for covering or encompassing the at least a part of the marine object may be used in the system according to the invention.

The invention further relates to an assembly of a system defined in the foregoing and a marine object such as a drive unit for use with a vessel. As mentioned earlier, it may be advantageous if the marine object comprises at least one transparent part that is configured to allow anti-biofouling light emitted by the system in the activated state thereof to pass through. According to another or an additional possibility, the marine object may be especially designed so as to avoid as much as possible that a component of the marine object to be irradiated with anti-biofouling light is in the shadow of another component.

The invention does not only relate to a system designed to realize an anti- biofouling effect on a marine object such as a drive unit for use with a vessel and to an assembly of such a system and a marine object as mentioned. The fact is that the invention further involves a method for arranging the system with respect to at least a part of a marine object as mentioned, and also a method of controlling operation of the system, for putting the system in the activated state whenever appropriate. The latter method may at least involve determining an on/off condition of the at least one light source of the system in cases in which the at least one light source is not operated continuously. This may be done in any suitable manner, for example by following a protocol determining a repetitive sequence of a time that the at least one light source should be operated and a time that the at least one light source does not need to emit anti-biofouling light. Depending on the design of the system according to the invention, controlling operation of the system may further involve a step of moving at least one component of the system with respect to the marine object in order to put the at least one component in any desired/predetermined position with respect to the marine object. The system may comprise any suitable kind of controller for controlling operation of the system in an automatic manner by following preprogrammed algorithms and/or in a manual manner on the basis of input provided by a human operator.

In the context of the invention, the following considerations may be relevant. In the case that the system according to the invention is designed to realize an anti-biofouling effect on a drive unit for use with a vessel, the system according to the invention may be intended to be used only when the drive unit is not operated to drive the vessel. On the other hand, it is possible for the system to be used independently of whether or not the drive unit is operated. Further, taking into account the fact that anti-biofouling light may be harmful to human beings and other living beings such as sea mammals, which is known to be the case when UV-C light is used, the design of the system may be chosen such that the extent to which anti-biofouling light is emitted to the system’s environment in the activated state of the system is minimized. Still further, any possible practical way of powering the at least one light source of the system is covered by the invention, including using batteries, having means for generating electric power on the basis of one or more environmental aspects such as motion and temperature difference, providing wireless transfer of electric energy through coils, etc.

The above-described and other aspects of the invention will be apparent from and elucidated with reference to the following detailed description of a number of possible embodiments of a system that is designed to realize a light-based anti-biofouling effect on a drive unit for use with a vessel. BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be explained in greater detail with reference to the figures, in which equal or similar parts are indicated by the same reference signs, and in which:

Fig. 1 diagrammatically shows a side view of a drive unit as mounted to a vessel, and illustrates a first embodiment of an anti-biofouling system according to the invention;

Fig. 2 diagrammatically shows a bottom view of a drive unit as mounted to a vessel, and illustrates a second embodiment of an anti-biofouling system according to the invention;

Fig. 3 diagrammatically shows a bottom view of a drive unit as mounted to a vessel, and illustrates a third embodiment of an anti-biofouling system according to the invention;

Fig. 4 illustrates a fourth embodiment of an anti-biofouling system according to the invention;

Fig. 5 diagrammatically shows a side view of a drive unit as mounted to a vessel, and illustrates a fifth embodiment of an anti-biofouling system according to the invention;

Fig. 6 diagrammatically shows a side view of a drive unit as mounted to a vessel, and illustrates a sixth embodiment of an anti-biofouling system according to the invention;

Fig. 7 diagrammatically shows a partially sectional side view of a bellows as may be part of a drive unit for use with a vessel, and illustrates a seventh embodiment of an anti-biofouling system according to the invention; and

Fig. 8 diagrammatically shows a perspective view of a bellows as may be part of a drive unit for use with a vessel, and illustrates an eighth embodiment of an anti- biofouling system according to the invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The invention is in the context of realizing an anti-biofouling effect on a marine object by means of anti-biofouling light. Various feasible embodiments of the system are illustrated in the figures and the particulars of those embodiments and other possibilities existing within the framework of the invention are described and explained in the following. All of those embodiments are in the context of a drive unit 100 for use with a vessel 200, which does not need to be understood so as to imply that the invention is limited to that context nor to imply that all particulars of the various systems described in the following are intrinsically linked to that context.

The vessel 200 has a hull 201, and a part of the hull 201 is shown in Figs. 1-5. The drive unit 100 has a motor part that is positioned in the interior of the vessel 200 and an outside drive part 101 that extends externally from the hull 201 of the vessel 200 and is therefore present in an aqueous environment when the vessel 200 is in the water. Only the outside drive part 101 is visible in Figs. 1-6. Among other things, the outside drive part 101 includes a propeller arrangement 102 that is driven by the motor part through transmission components for providing the vessel 200 with thrust, a tilting rod arrangement 103 for allowing the outside drive part 101 to be tilted with respect to the vessel 200, between an operable position and an upwardly tilted position, a mounting arrangement 104 at the end of the outside drive part 101 where the outside drive part 101 is attached to the vessel 200, and a tubular bellows 105 for allowing water to be taken in to the motor part for cooling purposes.

Fig. 1 illustrates an anti-biofouling system 1 according to a first embodiment of the invention. The anti-biofouling system 1 is in an assembly 15 with a drive unit 100 as mounted to a vessel 200, and activatable to irradiate at least a part of the outside drive part 101 of the drive unit 100 with anti-biofouling light. In the shown example, the anti-biofouling system 1 comprises two sheet-like/panel-like light emission bodies 10a, 10b that are movable about a hinge 11a, 1 lb and that are provided with a number of discrete light sources 12 that are configured to emit anti-biofouling light. A first configuration of the anti-biofouling system 1 is associated with a rest state of the system 1 in which the light emission bodies 10a, 10b are stowed against the hull 201 of the vessel 200, as indicated in Fig. 1 by means of dashed lines, acting more or less as an additional layer to the hull 201 that is hardly of any influence to the general configuration of the combination of the vessel 200 and the outside drive part 101 and the aquadynamic properties associated therewith. Not only are the light emission bodies 10a, 10b in a position as mentioned in the rest state of the anti-biofouling system 1, also the light sources 12 are in a deactivated state. A second configuration of the anti-biofouling system 1 is associated with an activated state of the system 1 in which the light emission bodies 10a, 10b have been hinged from the position associated with the rest state of the system 1 towards each other, so as to more or less enclose the outside drive part 101 between them, as indicated in Fig. 1 by means of continuous lines. Not only are the light emission bodies 10a, 10b in the hinged position as mentioned in the activated state of the anti-biofouling system 1, also the light sources 12 are in an activated state so as to perform an anti-biofouling action on the outside drive part 101 under the influence of the anti-biofouling light emitted from the light sources 12.

It is practical if the rest state is the default state of the anti-biofouling system 1. Actions of moving the anti-biofouling system 1 between the rest state to the activated state may be performed according to any suitable schedule. For example, the state of the anti- biofouling system 1 may be changed from the rest state to the activated state during a predetermined limited time period only, one or more times per 24 hours or another time unit when the outside drive part 101 is in an aqueous environment. The state of the anti-biofouling system 1 may be set by means of a preprogrammed control device that may also be adapted to allow manual manipulation of the system 1.

The light emission bodies 10a, 10b may have any suitable shape. Preferably, the light emission bodies 10a, 10b are shaped so as to be capable of facing each other with the outside drive part 101 between them, as shown in Fig. 1, as in that case, an anti- biofouling impact of the anti-biofouling system 1 can be optimal while loss of anti-biofouling light to the environment can be kept to a minimum. If the light emission bodies 10a, 10b are positioned so as to emit light in a direction that is mainly towards the hull 201 of the vessel 200, use of the anti-biofouling system 1 is optimally safe for human beings and other living beings as may be present in the vicinity of the vessel 200 and the outside drive part 101. Further, in that case, the anti-biofouling system 1 is effective in realizing anti-biofouling of the relatively complex and irregular structure of the mounting arrangement 104 at the end of the outside drive part 101 where the outside drive part 101 is attached to the vessel 200. In practice, this may involve a configuration of the anti-biofouling system 1 in which the light emission bodies 10a, 10b are connected to an area of the outside drive part 101 that is at a distance from the hull 201 of the vessel 200 such as an area of the outside drive part 101 that may be denoted as being a most rearward area of the outside drive part 101 as seen in a front- rear direction defined from the vessel 200 towards the outside drive part 101. In such a case, the light emission bodies 10a, 10b may be arranged to closely cover the outside drive part 101 in the rest state of the anti-biofouling system 1 and to open for facing both the outside drive part 101 and a portion of the vessel 200 as present in front of the outside drive part 101 in the activated state of the system 1.

In the shown example, the light emission bodies 10a, 10b have a generally curved shape, but other shapes are feasible as well, such as a planar shape as shown in Figs. 2 and 3. Further, in the shown example, the light emission bodies 10a, 10b are mounted on the hull 201 of the vessel 200 through the hinges 1 la, 1 lb, but is it also possible for the light emission bodies 10a, 10b to be mounted at another position, as mentioned earlier, such as on the outside drive part 101, as shown in Fig. 3. The hinges 11a, l ib can be linear hinges, and, assuming a normal, operable orientation of the vessel 200, the hinges 1 la, 1 lb can extend in a substantially horizontal direction, as shown in Fig. 1, or in any other appropriate direction, such as a substantially vertical direction as shown in Figs. 2 and 3.

The anti-biofouling system 1 according to the invention may include any type of light source. Also, the number of light sources 12 can be chosen freely within the framework in the invention. It is possible to use a number of UV-C LEDs in the anti- biofouling system 1, for example, but many alternatives are feasible, including alternatives in which both a light-generating device and some kind of light-guiding device are used. The at least one light source 12 of the anti-biofouling system 1 may be designed to emit light in any suitable range of directions, such as a limited range of directions, wherein the at least one light source 12 may even be of the type that is denoted as unidirectional in practice.

The activated state of the anti-biofouling system 1 according to the invention does not necessarily need to involve having both light emitting bodies 10a, 10b in the hinged position, as it may be possible to move the light emitting bodies 10a, 10b independently from each other and to put only one light emitting body 10a, 10b to a hinged position at a time.

Fig. 2 illustrates an anti-biofouling system 2 according to a second embodiment of the invention. When a comparison is made to the anti-biofouling system 1 according to the first embodiment of the invention, it is found that the basic principles of the two anti-biofouling systems 1, 2 are the same, whereas differences are found in the shape of the light emission bodies 10a, 10b and the orientation of the hinges 11a, 1 lb. As mentioned earlier, in the anti-biofouling system 2 according to the second embodiment of the invention, the light emission bodies 10a, 10b have a planar shape and the hinges 11a, l ib have a vertical orientation so that when the light emission bodies 10a, 10b are put to the hinged position and the light sources 12 are activated, the anti-biofouling light is emitted from the light emission bodies 10a, 10b to the outside drive part 101 from the sides of the outside drive part 101 rather than from what would normally be denoted as the bottom and the top of the outside drive part 101.

Fig. 3 illustrates an anti-biofouling system 3 according to a third embodiment of the invention. When a comparison is made to the anti-biofouling system 2 according to the second embodiment of the invention, a difference is found in the fact that in the anti- biofouling system 3 according to a third embodiment of the invention, the hinges 11a, l ib are arranged on the outside drive part 101 so that the light emission bodies 10a, 10b are connected to the outside drive part 101. In the shown example, the size of the light emission bodies 10a, 10b is chosen so as to cover only a limited area of the outside drive part 101.

Each of the light emission bodies 10a, 10b can be moved from one stowed position against the outside drive part 101 to another, as indicated in Fig. 3. In a first section of the moving range, the light emission body 10a, 10b can be used to emit light to one area of the outside drive part 101, and in a second section of the moving range, the light emission body 10a, 10b can be used to emit light to another, adjacent area of the outside drive part 101. A notable feature of the anti-biofouling system 3 is that the system 3 can very well be used for subjecting the mounting arrangement 104 at the end of the outside drive part 101 where the outside drive part 101 is attached to the vessel 200 to an anti-biofouling action, opening to the mounting arrangement 104 from a position that is further rearward on the outside drive part 101 as seen in a front-rear direction defined from the vessel 200 towards the outside drive part 101 for a part of the moving range. In the shown example, the light emission body 10a, 10b is equipped with light sources 12 at both sides in order to realize the desired light emission towards the outside drive part 101 in every possible position of the light emission body 10a, 10b. Alternatively, the hinge 11a, 1 lb can be provided in the form of a ball hinge or the like, in which case the light emission body 10a, 10b can be turned around a

longitudinal axis thereof so that having light sources 12 at only one side may suffice for achieving that light can be emitted from the light emission body 10a, 10b towards the outside drive part 101 in every possible position of the light emission body 10a, 10b.

Fig. 4 illustrates an anti-biofouling system 4 according to a fourth embodiment of the invention. Also this embodiment relies on having a light emission bodies 10a, 10b that are movable to a position for emitting anti-biofouling light to the outside drive part 101 in the activated state of the anti-biofouling system 4. In this case, a plurality of light emission bodies 10a, 10b, ..., 1 Ox is used, wherein the light emission bodies 10a, 10b, ..., lOx are provided as the ribs of a foldable dome awning-like device 40 that can be pulled up or fully pulled out to encompass the outside drive part 101, the light emission bodies 10a, 10b, lOx being provided with light sources 12. Fig. 4 shows the dome awning-like device 40 in a state of being fully pulled out. In the shown example, the light emission bodies 10a, 10b, lOx are generally U-shaped, the ends of the light emission bodies 10a, 10b, ..., lOx being hingably connected to the hull 201 of a vessel 200. Between the light emission bodies 10a, 10b, ..., lOx, flexible and/or foldable intermediate material 41 may be present, although this is not necessary. If intermediate material 41 is present, indeed, it may be so that the anti- biofouling system 4 is equipped with light sources 12 that are located at the position of the light emission bodies 10a, 10b, ..., lOx and/or at the position of the intermediate material 41.

An advantage of the anti-biofouling system 4 according to the fourth embodiment of the invention resides in the generally closed appearance of the system 4 in the activated state thereof. On the basis of such appearance, it is achieved that the anti-biofouling light that is emitted by the light sources 12 in the activated state of the system 4 is mainly kept inside the area defined between the hull 201 of the vessel 200 and the light emission bodies 10a, 10b, ... , lOx. In the case of intermediate material 41 being present between the light emission bodies 10a, 10b, ..., lOx, the intermediate material 41 may be chosen so as to be impermeable to the anti-biofouling light so that impact of the anti-biofouling light on the environment is further minimized.

Besides the dome awning-like device 40 including the light emission bodies 10a, 10b, ... , lOx, the light sources 12, the optional intermediate material 41 between the light emission bodies 10a, 10b, ..., lOx, and an arrangement for realizing a hinged connection of the light emission bodies 10a, 10b, ..., lOx to the hull 201 of the vessel 200, the anti- biofouling system 4 according to the fourth embodiment of the invention may comprise a suitable housing for storing the dome awning-like device 40 in the rest state of the system 4.

It is possible to have brushes or the like in the vicinity of such a housing, on such a housing and/or in such a housing in order to clean the dome awning-like device 40 when it retracts to the housing. Additionally or alternatively, it is possible to apply a light-based anti-biofouling solution for counteracting biofouling on areas of the dome awning-like device 40 that are not covered by the anti-biofouling light for realizing anti-biofouling of the outside drive part 101 in case it is intended to have the anti-biofouling system 4 in the activated state thereof for quite some time. The dome awning-like device 40 may be positioned and dimensioned so as to encompass the outside drive part 101 in its entirety against the hull 201 of the vessel 200, but other possibilities exist as well, particularly the possibility of the dome awning-like device 40 being positioned and dimensioned to cover only a part of the outside drive part 101.

Fig. 5 illustrates an anti-biofouling system 5 according to a fifth embodiment of the invention. In this embodiment, the anti-biofouling system 5 comprises inflatable bodies 50a, 50b on which light sources 12 are arranged, and is thereby an example of a system that includes a deployable arrangement that is movable between an activated position associated with the activated state of the system and an inactivated position. Besides the inflatable bodies 50a, 50b and the light sources 12, the system 5 comprises means 51 designed to inflate or deflate the inflatable bodies 50a, 50b.

In the example illustrated in Fig. 5, the inflatable bodies 50a, 50b have a generally elongated shape in the activated position thereof and are arranged so as to shine anti-biofouling light towards different areas of the outside drive part 101. It is to be noted that when it comes to the concept of using inflatable bodies 50a, 50b for the purpose of moving light sources 12 to an operable position and back to a stowed position, many possibilities exist, wherein the inflatable bodies 50a, 50b can be of any suitable shape and size, and wherein any suitable number of inflatable bodies 50a, 50b can be used, including just a single one. Other options that may be practical are the option of having a sleeve-like inflatable body that is inflated so as to encompass at least a part of the outside drive part 101 and the option of having a bag-like inflatable body that is inflated so as to enclose the outside drive part 101 and to have the outside drive part 101 in the interior thereof. In the latter case, the bag-like inflatable body may not only be used for shining anti-biofouling light towards the outside drive part 101, but may also have a function in creating a sealed space around the outside drive part 101 so that any liquid present in the space can be sterilized by means of the anti- biofouling light or liquid can be evacuated from the space and optionally be replaced by anti- biofouling chemicals.

In the anti-biofouling system 5 that is equipped with at least one inflatable body 50a, 50b, the at least one light source 12 of the system 5 can have any appropriate position. Practical possibilities in respect of the position as mentioned include one or more of a position at an exterior surface of an inflatable body 50a, 50b, a position at an interior surface of an inflatable body 50a, 50b, a position in the material making up the inflatable body 50a, 50b, and a position in an interior space of the inflatable body 50a, 50b. In respect of the latter possibility, it is noted that assuming that the inflatable body 50a, 50b is filled with air or another appropriate gas in the activated position thereof, there is hardly any absorbing effect on the anti-biofouling light inside the inflatable body 50a, 50b, so that the anti-biofouling light can be emitted from the inflatable body 50a, 50b in a manner that is practically as effective as would be the case when the at least one light source 12 would be arranged in and/or on the material making up the inflatable body 50a, 50b.

Further, when at least one inflatable body 50a, 50b is applied in the anti- biofouling system according to the invention, it is possible for the system to comprise a combination of the at least one inflatable body 50a, 50b and one or more non-inflatable parts. For example, the at least one inflatable body 50a, 50b may be designed so as to act like a kind of extendable/retractable mast carrying a number of sheet-like/panel-like non-inflatable transverse elements.

Fig. 6 illustrates an anti-biofouling system 6 according to a sixth embodiment of the invention. In this embodiment, the anti-biofouling system 6 includes at least one light source 12 that is configured to be fixedly arranged on the vessel 200, on the drive unit 100 and/or in the drive unit 100. In particular, in the shown example, the light source 12 comprises a tubular lamp or an elongated strip of LEDs or the like that is fixed to the outside drive part 101 at a position for emitting anti-biofouling light towards the tilting rod arrangement 103, as indicated in Fig. 6 by means of a number of arrows.

The example illustrated in Fig. 6 is just one representative of numerous possibilities of having one or more light sources 12 in a fixed arrangement in or on the outside drive part 101. It may also be practical to provide the at least one light source 12 in a (transparent) wall element of the outside drive part 101. Further, as mentioned, it is also possible for the vessel 200 to be equipped with one or more light sources 12 for shining anti- biofouling light towards the outside drive part 101. In the anti-biofouling system 6 according to the sixth embodiment of the invention, putting the system 6 to the activated state may only involve switching on the at least one light source 12 without a need for having a certain movement for bringing the at least one light source 12 to a certain place.

Figs. 7 and 8 illustrate an anti-biofouling system 7 according to a seventh embodiment of the invention and an anti-biofouling system 8 according to an eighth embodiment of the invention, respectively, both of which are designed to be used for performing an anti-biofouling action on the tubular bellows 105 as may be part of the outside drive part 101. It is understood that due to the very constructional nature of the bellows 105, especially the presence of a pattern of grooves and ridges, the bellows 105 is very much susceptible of biofouling.

Within the framework of the invention, various possibilities for obtaining an anti-biofouling effect on a bellows 105 by using anti-biofouling light exist, a number of which will now be addressed. In the first place, as illustrated in Fig. 7, it is possible that an anti-biofouling system 7 having fiber-like light emission elements 70a, 70b, ..., 70x is applied, which fiber-like light emission elements 70a, 70b, ..., 70x may be provided as separate rings around the bellows 105 or as ring-shaped sections of a single elongated fiber body. Preferably, as shown, such fiber-like emission elements 70a, 70b, ..., 70x are arranged between the ridges of the bellows 105, i.e. at the position of the grooves of the bellows 105. The fiber-like emission elements 70a, 70b, ..., 70x may be adapted to emit anti-biofouling light in any suitable way, for example through a number of discrete light sources 12. In the second place, as illustrated in Fig. 8, it is possible that a sleeve-shaped carrier 71 that is adapted to encompass the bellows 105 and that is provided with a number of light sources 12 is used. The light sources 12 may be arranged in and/or on the material of the sleeve-shaped carrier 71, wherein it may be practical for the material of the sleeve-shaped carrier 71 to be transparent to the anti-biofouling light. In Fig. 8, the sleeve-shaped carrier 71 is depicted as having two halves and being in a state prior to full closure of those halves around the bellows 105. In the third place, the bellows 105 itself may be used as a carrier of light sources 12, preferably of relatively small light sources 12 such as UV-C LEDs. The bellows 105 may be designed so as to be at least partially transparent, and the light sources 12 may be arranged at the interior surface of the bellows 105 in that case and/or may be embedded in the material of the bellows 105. Having a bellows 105 that is at least partially transparent also offers a possibility of having a light source 12 that extends in the interior space of the bellows 105 and still achieving anti-biofouling effects on the exterior surface of the bellows 105.

Emitting anti-biofouling light to and/or away from the bellows 105 may involve using light sources 12 at a fixed arrangement with respect to the bellows 105, as suggested in the foregoing, but it is also possible to use light sources 12 that are arranged so as to be movable with respect to the bellows 105. The solutions explained in the foregoing are not exclusive to the bellows 105 of the outside drive part 101, but may also be applied to other components/areas of the outside drive part 101 in a similar or comparable manner insofar as this is not prohibited by design aspects of the other components/areas. In general, it is noted that it may be so that the above explanation of the invention provided with reference to the figures is in the context of vessels 200 and drive units 100 of vessels 200, but that is not to be understood so as to mean that the invention would not be applicable to other contexts. In this respect, it is noted that the skilled person does not have any difficulty in understanding that the invention is at the level of the anti-biofouling system to be used with some kind of marine object, or at least a part thereof, and that the drive unit 100 is no more than one practical example of such an object.

In general, the invention covers all possible situations in which it may be desirable to subject at least a part of a marine object such as a drive unit 100 that can be activated so as to perform a certain function or that can be switched off to an anti-biofouling action. With reference to the example of the drive unit 100, it is possible to control the system according to the invention depending on whether or not the drive unit 100 is activated to drive a vessel 200, or is expected to be activated soon to do so. This may particularly be applicable to embodiments of the system including some kind of movable component(s). On the other hand, it is possible to control the system according to the invention according to a certain time schedule, for example.

It will be clear to a person skilled in the art that the scope of the invention is not limited to the examples discussed in the foregoing, but that several amendments and modifications thereof are possible without deviating from the scope of the invention as defined in the attached claims. It is intended that the invention be construed as including all such amendments and modifications insofar they come within the scope of the claims or the equivalents thereof. While the invention has been illustrated and described in detail in the figures and the description, such illustration and description are to be considered illustrative or exemplary only, and not restrictive. The invention is not limited to the disclosed embodiments. The drawings are schematic, wherein details that are not required for understanding the invention may have been omitted, and not necessarily to scale.

Variations to the disclosed embodiments can be understood and effected by a person skilled in the art in practicing the claimed invention, from a study of the figures, the description and the attached claims. In the claims, the word“comprising” does not exclude other steps or elements, and the indefinite article“a” or“an” does not exclude a plurality.

Any reference signs in the claims should not be construed as limiting the scope of the invention.

Elements and aspects discussed for or in relation with a particular embodiment may be suitably combined with elements and aspects of other embodiments, unless explicitly stated otherwise. Thus, the mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

The terms“comprise” and“include” as used in this text will be understood by a person skilled in the art as covering the term“consist of’. Hence, the term“comprise” or “include” may in respect of an embodiment mean“consist of’, but may in another embodiment mean“contain/have/be equipped with at least the defined species and optionally one or more other species”.

Notable aspects of the invention can be summarized as follows. In the context of anti-biofouling, a system is provided that is designed to realize an anti-biofouling effect on a marine object such as a drive unit 100 for use with a vessel 200, the system including at least one light source 12 that is configured to emit anti-biofouling light, and the system being arrangeable with respect to at least a part 101 of the marine object, for emitting the anti- biofouling light towards, in and/or away from the marine object in an activated state of the system. It may be advantageous for the system to include at least one movable component 10a, 10b, ..., lOx that is configured to be movably arranged with respect to the marine object, wherein optionally at least one light source 12 of the system 1 is arranged on the at least one movable component 10a, 10b, ..., lOx.