Speleonaut
Speleonaut (named from the Greek words for "cave" and "sailor") is the submersible used by the cave diver Jochen Hasenmayer. After the 1989 decompression accident that left his legs paralyzed, Hasenmayer designed the "Speleonaut" with his friend Konrad Gehringer in order to continue exploring the Blauhöhle cave system, which begins at the base of the Blautopf spring in the Swabian Jura mountain range. The "Speleonaut" is wide and has nine engines, making it easy to maneuver in all directions. It is the first submarine designed specifically for the exploration of caves. According to Hasenmayer, the "Speleonaut" has been tested  in Lake Constance to a depth of and has a design limit of . The "Speleonaut" was first used at the Blautopf in 1996. In 2001 Hasenmayer reached the "Mörikedom" ("Mörike cathedral") chamber of the Blauhöhle, which he had discovered in 1985, in the "Speleonaut". In 2004 he reached a point beyond the "Mörikedom" into the mountain. In the same year he discovered two more large chambers in the Blauhöhle: the "Mittelschiff" (or "nave") and the "Äonendom".