Abstract: A buoyant device has a body and an elongate tail. The body carries a payload. The tail is moveable, e.g. by pivoting, between a closed and an open position. This movement changes the position of the center of mass of the device relative to the center of buoyancy. As a result the device can move through the water, with the tail in the closed position, with minimal drag. However, when the tail moves to the open position, the body pivots in the water so that the body, and hence the payload is supported in a stable manner.

Abstract: An apparatus for towing behind an underwater vehicle has a body and a yoke pivotally connected to the body at a pivot point and having a tether remote from the pivot point by which the apparatus us towed. The yoke has wings which generate a resultant force on the body when the apparatus is towed. By varying the orientation of the yoke relative to the body, the magnitude of the resultant force may be varied. The resultant force tends to reduce the displacement of the tether relative to the pivot point in at least one plane, thereby generating a force to counter the buoyancy of the apparatus, and so stabilize the apparatus when it is being towed.

Abstract: A buoyant device has a body and an elongate tail. The body carries a payload. The tail is moveable, e.g. by pivoting, between a closed and an open position. This movement changes the position of the center of mass of the device relative to the center of buoyancy. As a result the device can move through the water, with the tail in the closed position, with minimal drag. However, when the tail moves to the open position, the body pivots in the water so that the body, and hence the payload is supported in a stable manner.