To make it possible to easily install an aeration/circulation apparatus and a towed self-submerging type anchor under water in a dam lake, lake or marsh without carrying large machinery and materials in the dam lake, lake or marsh.

An aeration/circulation apparatus A and a towed self-submerging type anchor B are moored to each other by using a chain 2 and a swivel 3 to be connected to each other. Air is injected into a buoyancy tank 13 of the towed self-submerging type anchor. By using the buoyancy, the aeration/circulation apparatus A and the towed self-submerging type anchor B are towed to an installation place. At the installation place, the air in the buoyancy tank 13 is exhausted, and the towed self-submerging type anchor B is allowed to submerge and is installed under water together with the aeration/circulation apparatus A. Even if the towed self-submerging type anchor B rotates when submerging, an air supply hose 12 is not twisted, so that the aeration/circulation apparatus A and the towed self-submerging type anchor B can be easily installed under water subsequently to a state of being connected near the water surface. As a result, after the towed self-submerging type anchor B reaches the bottom, diving work of connecting the air supply hose 12 for aeration is not required. The aeration/circulation apparatus and the towed self-submerging type anchor may be integrated by using a connection member.