Is splunking dangerous?
Caving
Caves can be dangerous places; hypothermia, falling, flooding, falling rocks and physical exhaustion are the main risks. Rescuing people from underground is difficult and time-consuming, and requires special skills, training, and equipment. Full-scale cave rescues often involve the efforts of dozens of rescue workers (often other long-time cavers who have participated in specialized courses, as normal rescue staff are not sufficiently experienced in cave environments), who may themselves be put in jeopardy in effecting the rescue. This said, caving is not necessarily a high-risk sport (especially if it does not involve difficult climbs or diving). As in all physical sports, knowing one's limitations is key.
Rafting
Risks in white water rafting stem from both environmental dangers and from improper behavior. Certain features on rivers are inherently unsafe and have remained consistently so. These would include ‘keeper hydraulics’, ‘strainers’ (e.g. fallen trees), dams (especially low-head dams, which tend to produce river-wide keeper hydraulics), undercut rocks, and of course dangerously high waterfalls. Even in safe areas, moving water can always present risks—such as when a swimmer attempts to stand up on a rocky riverbed in strong current, risking foot entrapment. Irresponsible behavior related to rafting while intoxicated has also contributed to many accidents.