Overview of cave climbing
Climbing in caves is considerably different than traditional climbing disciplines on the surface. Climbing while underground is done purely for the purposes of exploration, i.e. to reach the top in the hope of finding continuing passage. We do not chose a climbing route for its recreational quality, and most climbs are only ever done once. There are no rules for the quality or style of the ascent. It is only important to reach the top safely, and to minimize impacts in the process. Where caves are located in designated Wilderness Areas, power drills are not permitted, which adds to the difficulty and risk. The techniques used to ascend vertical pitches underground are an amalgam of free-climbing, traditional climbing, aid climbing and canyoneering.
The strategies and gear needed for technical climbing underground can vary significantly depending on the geology (rock type and quality), how much mud and water is involved, length and complexity of the route, remoteness, and any restrictions (e.g. a ban on drilling).
General strategies and gear
The default fall-back option for ascending a vertical pitch in a cave is to use direct aid techniques, which involves placing a piece of protection in the cave wall, attaching aiders to that placement, climbing as high as possible in the aiders, and repeating the process. Aid climbing is slow, tiring, potentially risky, and requires a lot of heavy equipment. In many cases the need to aid climb can be avoided by looking for creative alternatives. If the route being considered is low angle and has good hand and foot holds, it may be possible to free-climb, which generally requires fewer gear placements and therefore can be done faster. Many pitches also have features such as natural bridges, stalagmites, or spires that may be good targets for a rope toss. Cavers have been very creative in finding ways to get a fishing line or lightweight cord over a natural feature high up in a dome or ceiling alcove, that can then be used to pull up progressively stronger cords or ropes. Some of the usual strategies include attaching a heavy object to a line that can be tossed by hand (e.g. rock, tennis ball, water bottle, throw-bag with rock inside, bolting hammer). The practical limit for hand tossing is about 40 feet. This approach requires that the object being thrown gets over or around the target of interest, and also makes its way back to the ground so that a heavier rope can be pulled into place, and one end can be secured to an anchor on the ground.