Joachim Wendler

Wendler, a 36-year-old experienced diver, and two other German aquanauts began the two-day/two-night checkout mission on September 21, 1975. All three divers were employees of the German firm Gesellschaft fur Kernenergieverwertung in Schiffbau und Schiffahrt mbH (GKSS), which operated the Helgoland Habitat. On September 23 the three Germans were joined by two American divers: Lieutenant Commander Laurence Bussey of the United States Navy, the head of the project for the National Oceanic and Atmospheric Administration (NOAA), and Roger Clifford, a fisheries scientist from NOAA's laboratory at Woods Hole. Wendler, Bussey, and another of the German aquanauts, Joachim Rediske, proceeded to undergo a 49-hour decompression inside Helgoland, which was completed at 6:30 p.m. on September 24. Their return to the surface was then delayed by 15 hours due to bad weather and in order to enable them to surface in daylight.

On November 21, 1975, an American aquanaut experienced either central nervous system bends or an embolism on surfacing from Helgoland; he was successfully treated but experienced some residual disability. Captain Bond later said that the FISSHH project had as many serious safety incidents as he could remember in a project of similar length. Joachim Wendler was the world's second aquanaut to die as a result of participating in an underwater habitat project, the first having been SEALAB III aquanaut Berry L. Cannon.

Joachim Wendler (June 6, 1939, in Erfurt, Germany – September 25, 1975, in Rockport, Massachusetts) was a West German aquanaut who died of an air embolism while returning to the surface of the Gulf of Maine from the Helgoland underwater habitat. He was participating in a checkout mission for the First International Saturation Study of Herring and Hydroacoustics (FISSHH) project.