To provide a small planing boat or the like of a composition with easy demounting and mounting of an engine from a hull.

The small planing boat is provided with a water jet pump P driven by the engine E arranged in an engine room having an opening in an upper part, and it is composed so that it is propelled by reaction of water pressurized and accelerated at the water jet pump P and jetted from a rear nozzle. It is composed so that at least one of an exhaust pipe connecting end face Pe1, an intake pipe connecting end face Pi1 and an attaching face Ck1 of an oil filter of an engine body Eb is positioned inside the opening 16 as seen from a direction perpendicular to an opening face of the opening 16.