Alumina ceramic 10 in flotation spheres for deep submergence ROV/AUV systems

A casting process for ceramic spherical flotation units with nominal 10 in OD has been developed by Custom Ceramic Technology utilizing 99.9 percent Al/sub 2/O/sub 3/ for operation on an ROV/AUV in all ocean depths. With their 0.42 weight to displacement ratio, they provide more lift per pound of their dead weight in air than syntactic foams for 36,000 ft (11,000 m) depths. With their critical implosion pressure of /spl ges/37,000 psi (255 MPa) they provide a margin of safety >2 for operation at 36,000 ft (11,000 m), >4 at 20,000 ft (6097 m) and >8 at 10,000 ft (3,048 m). Because of their high margin of safety at depths /spl les/20,000 ft they are also acceptable for service on manned submersibles at depths /spl les/20,000 ft (6097 m).