A buoyancy device (1) comprises a support structure 2, 4 which can be connected to an underwater application (3) and one or more buoyancy spheres (4) having a specific weight of less than 500 kg/m.sup.3 connected to the support structure (2) and having a light metal spherical shell (5) defining a spherical inner volume (6) and which has an outer diameter (d) greater than 0.5cm, and a radial thickness (t) greater than 0.08mm, wherein the spherical shell (5) is obtained in one piece in nano-crystalline metal with an average grain size of less than 1000 nanometers.

A buoyancy device (1) comprises a support structure 2, 4 which can be connected to an underwater application (3) and one or more buoyancy spheres (4) having a specific weight of less than 500 kg/m.sup.3 connected to the support structure (2) and having a light metal spherical shell (5) defining a spherical inner volume (6) and which has an outer diameter (d) greater than 0.5cm, and a radial thickness (t) greater than 0.08mm, wherein the spherical shell (5) is obtained in one piece in nano-crystalline metal with an average grain size of less than 1000 nanometers.

A personal watercraft includes: a watercraft body; a handlebar provided on an upper front part of the watercraft body; a seat provided on an upper part of the watercraft body and extending in a front-rear direction behind the handlebar; and a pair of floats provided so as to protrude outward in a watercraft width direction from left and right side surfaces of the watercraft body in order to additionally give buoyancy to the watercraft body. Each of the floats extends in the front-rear direction alongside the seat and is arranged limitedly in a region behind the handlebar.

A personal watercraft includes: a watercraft body; a handlebar provided on an upper front part of the watercraft body; a seat provided on an upper part of the watercraft body and extending in a front-rear direction behind the handlebar; and a pair of floats provided so as to protrude outward in a watercraft width direction from left and right side surfaces of the watercraft body in order to additionally give buoyancy to the watercraft body. Each of the floats extends in the front-rear direction alongside the seat and is arranged limitedly in a region behind the handlebar.

The invention relates to a floating foundation for wind turbine generators and a method for installing a wind turbine generator on top of and performing maintenance on said foundation. The floating foundation includes a tower and two support legs pivotally connected to the tower, forming a tripod-like structure. The floating foundation may include hydrodynamic damping elements and a single point mooring system leaving the foundation free to weathervane. The invention also relates to a method for using the structure as a crane, lowering and raising the turbine platform against and from e.g. a service barge during maintenance or assembly.

The invention relates to a floating foundation for wind turbine generators and a method for installing a wind turbine generator on top of and performing maintenance on said foundation. The floating foundation includes a tower and two support legs pivotally connected to the tower, forming a tripod-like structure. The floating foundation may include hydrodynamic damping elements and a single point mooring system leaving the foundation free to weathervane. The invention also relates to a method for using the structure as a crane, lowering and raising the turbine platform against and from e.g. a service barge during maintenance or assembly.

The present invention relates to a winged boat comprising a main body including a passenger space and a closed space at an edge, buoyant wing parts protruding from both sides of the main body, disposed in a front and a rear area of the main body, and each including a wing body protruded from a side of the main body; a buoyant space formed inside the wing body in a closed state; a water storage part disposed in an opposite direction to the main body with respect to the buoyant space and having an opening and closing part at a lower portion and an inlet formed at an upper portion, and a buoyancy control part provided in an opposite direction to the buoyant space with respect to the water storage part and adjusting buoyancy of the wing body by controlling an amount of water stored therein.

The present invention relates to a winged boat comprising a main body including a passenger space and a closed space at an edge, buoyant wing parts protruding from both sides of the main body, disposed in a front and a rear area of the main body, and each including a wing body protruded from a side of the main body; a buoyant space formed inside the wing body in a closed state; a water storage part disposed in an opposite direction to the main body with respect to the buoyant space and having an opening and closing part at a lower portion and an inlet formed at an upper portion, and a buoyancy control part provided in an opposite direction to the buoyant space with respect to the water storage part and adjusting buoyancy of the wing body by controlling an amount of water stored therein.

An internal canoe frame acts as a mount for retractable outriggers, foldable panels, and pontoons. With the outriggers, panels, and pontoons, the canoe can be adapted to provide a stable multi-purpose waterborne platform. In some embodiments, the platform may also include a support frame for a tent, to provide a waterborne camping site for an intrepid canoer.

An internal canoe frame acts as a mount for retractable outriggers, foldable panels, and pontoons. With the outriggers, panels, and pontoons, the canoe can be adapted to provide a stable multi-purpose waterborne platform. In some embodiments, the platform may also include a support frame for a tent, to provide a waterborne camping site for an intrepid canoer.