(under subclass 185) Method or apparatus wherein the means with which personnel may carry on the underwater operation comprises an enclosure confining a gaseous environment which is maintained at a pressure equal to or greater than the surrounding water pressure to prevent ingress of water
through an opening.
SEE OR SEARCH THIS CLASS, SUBCLASS:
8+, for pressurized pneumatic caissons which have a portion extending above the surface of the body of water within which it is located, which portion allows access to the interior of the caisson.
