A floation device includes a molded outer shell defining a hollow interior. The hollow interior is filled with recycled plastic bottles of the type used conventionally for soft drink containers which are molded from a plastic material and include a generally cylindrical body and a neck at one end of the body which is closed by a cap. The outer container is shaped with wall portions having a curvature equal to the outside curvature of the bottles and indentations for receiving the necks of the bottles which are aligned neck to neck in rows. The recycled bottles provide a filling for the rotational molded shell which prevent loss of buoyancy if the shell is perforated and prevent expansion and contraction problems due to temperature changes.

A flotation fabric is composed of two opposed layers of water permeable flexable woven or knitted material. Sandwiched between the layers are small particles, pellets or beads of closed cell foam plastic material. The cloth layers are joined together by stitching, heat sealing or adhesive to trap and flexibly immobilized the pellets between the layers to form a breathable flexible flotation fabric. Personal flotation devices or garments such as T shirts are made from the fabric. They are light weight, flexible, breathable and comfortable enough to be worn by a child at play and will allow a child to return to the surface and cry out for help to prevent drowning if the child falls in a body of water.

A cushioning device comprises a resilient foam material surrounded by a seamless, woven jacket that is gathered along opposed sides and stitched so that the gathered jacket forms attachment flanges that serve as means to fasten the cushioning device to a pier, loading dock, wall, or the like. The cushioning device is produced by inserting the foam center section down a woven jacket made from polyester, nylon, "NOMEX", "KEVLAR", or similar abrasion-resistant materials, the jacket having an internal diameter greater than the circumference of the foam center section. The excess jacket is gathered into flat portions that are stitched together to form the attachment flanges.

A variable-buoyancy marine riser and a method for providing and adjusting the buoyancy for such a riser. The riser is comprised of a main riser conduit on which a plurality of cans are affixed. A slurry of buoyant material, e.g. small, hollow spheres, is pumped into the cans to displace the seawater therein and give buoyancy to the riser. When it is desired to reduce the buoyancy of the riser, the spheres are removed by merely opening the cans and allowing the surrounding seawater to displace the spheres from the cans.