This paper describes test and checkout procedures for the Tektite ocean habitat system. The Tektite ocean habitat system is an underwater laboratory designed to support scientific and technical crews performing long term, shallow water diving experiments. In 1969, this system housed four aquanaut/scientists for a period of 60 days at a depth of 50 feet. The original experiment, sponsored by the Navy, verified the feasibility of the habitat as in-situ marine scientific laboratory and demonstrated its adequacy as a life support system. In April, 1970, the habitat began a program under the sponsorship of the Department of the Interior to support several five man teams, each performing two week scientific missions over a seven month time period.Testing and checkout of the habitat and its related systems, life support, power, communications, and water, involves activity both above and below the surface. First, the systems must be tested by engineers and technicians before the habitat is emplaced in the water. This insures that the habitat is in a ready condition, and verifies the ability of the systems to meet performance requirements. Finally, many system checks must be performed in the water after emplacement. Because divers are limited by the time they are permitted to remain at depth, these tests must be carefully designed and rehearsed to permit completion within prescribed time limits. The key to success under such conditions lies in careful test planning and scheduling, advance testing of equipment and materials, and utilization of diver trained engineers and technicians who are thoroughly trained on all systems.