There are some special forms for recreational divers, which often require special knowledge and in-depth training:
Ice diving: Ice diving is diving under a closed ice sheet. Particular dangers here are primarily the effect of the low water temperature on divers and equipment as well as the almost excluded possibility of finding the entrance opening without a guide line.
Historical diving: Lately, the interest in old diving technology has also increased among recreational divers. In particular, helmet diving devices, as they represented the state of the art between 1900 and 1950, but gradually disappeared from professional diving, are receiving new attention here. The focus here is on the experience of dealing with old technology, comparable to the hobby of classic cars.
Cave diving: Many caves are completely or partially filled with water, exploring them by diving is a special attraction. However, this is associated with dangers of their own kind, especially narrowness, darkness and the danger of losing orientation. As the cave diver usually has no possibility to emerge briefly in dangerous situations, he must have a particularly high degree of self-control and also take technical precautions. Above all, a significantly larger air supply, redundant equipment and the use of a guide line are used for this.
Orientation diving: Orientation diving is about fast and accurate diving. This competitive sport combines elements of orienteering and fin swimming.
Solo diving: Solo diving is not done with a buddy as usual. This has advantages from the perspective of some divers, but requires additional equipment and training.
Underwater photography and underwater video: With special cameras or conventional photo equipment in water and pressure-tight housings, it is possible to take photos and videos under water. This special form of photo and videography is not only used in the professional field, but also in diving.
Wreck diving: Shipwrecks are special attractions for divers, on the one hand out of interest in the sunken ship itself, but also because of the often remarkable flora and fauna that inhabit such artifacts as a new habitat. However, wreck diving poses dangers: different currents, stuck fishing nets, protruding, sharp edges and, if you penetrate the wreck, the risk of getting caught or getting stuck and losing your orientation.