traces in caves), according to lost or intentionally left things, etc .; involvement of specially trained search dogs, if the level of gas content in the cave allows it; use of acoustic search and night vision devices; along the sections divided between the search groups, wells, mines, corridors, floors of the cave. It is also possible to conduct a "free" search, in which one group of rescuers in a cave inspects all areas in a row, regardless of their complexity and danger. When finding the victims and providing them with the necessary first aid, it is necessary to remove them from the cave as soon as possible.

Types of transportation of victims are: manual, pack, mechanized. The priority for the victim is a mechanized method of transportation. Manual transportation is preferable using special, rather than "home-made" means. The victim must certainly be attached to the stretcher, due to the shaking that occurs during transportation, the fatigue of the rescuers can also subject him to falling from a special stretcher and receiving other injuries. It is possible to drag the victim in his arms only over short distances, since there is a very intense load on the rescuers' hands. Pack transportation in caves is faster than manual transportation, but its disadvantage is the considerable complexity of organization.

Caving Tactics
In caving, one has to solve tactical tasks that arise at five main stages: during its preparation, when moving to a chosen area, when searching, reconnaissance and passing through karst cavities, when carrying out topographic and research work in them, and at the end of the journey. The degree of preliminary development of tactical methods for exploring karst areas and the degree of their practical implementation during the trip can be different and are determined primarily by the composition of the participants and their training. However, the basis of any tactical plan must be to ensure maximum safety by all means - from thoughtful milestones, determined by the likely pace of work in a given cavity, to a contingency plan in the event of an emergency.

By systematizing the data, it is possible to divide the dangers of caving into two large groups: the dangers caused by the specifics of the underground world, and the dangers associated with insufficient technical training of the expedition members and the tactical mistakes they made.

The first group includes:
Natural landslides and rockfalls (ice + stone). They are most frequent in caves and mines laid in layered limestones and gypsum. This danger is usually exaggerated, since the stability of the vaults of the galleries of caves and domes of mines has been repeatedly tested by seismic activity. A significant danger is the collapse of ice deposits, which are annually formed in cold bag-shaped caves. The only possible precaution is the rapid passage of landslide areas while maintaining silence.

Water hazards. They exist both in constantly flooded and in periodically flooded caves. The most dangerous thing is a sudden rise in the level of groundwater during snowmelt and heavy rainfall. Usually the rise of water ranges from 2-3 to 10-15 m, but sometimes it reaches 50-90 (Skelskaya cave in the Crimea). The danger of drowning when overcoming streams and reservoirs with open water, as well as siphons, is combined with the danger of hypothermia (water temperature 2-10ºС). Must be able to swim, dive and be able to properly operate a wetsuit and rubber boat. Precautions - the right choice of places for base camps, control of maximum water levels in their wake (in the form of light or dark horizontal stripes on the wall), the presence of telephone communication with the surface, food supplies and lighting for forced stay underground for several days.

Accumulation of harmful gases. In most karst cavities of the USSR, large accumulations of harmful gases have not been found. Small accumulations of carbon dioxide (albeit 10-30 times higher than its content in atmospheric air) can be found in almost any cavity. This carbon dioxide is formed mainly due to the decay of organic residues, which are abundant in every cavity, and does not pose a danger to life. An increase in the content of carbon dioxide in the air of karst cavities to 4-5% (atmospheric air contains 0.03%) causes sweating, squeezing the head, tinnitus, mental agitation, and less often vomiting. However, this physiological effect is purely individual. An increase in the content of methane to 8-10% while maintaining a normal oxygen content does not cause any pain. But already with a methane content in the air from 3.1 to 16%, this mixture becomes explosive. Therefore, the limit of a person's stay in karst cavities and natural workings is 2% CH4 content.

Precautions - checking the air pollution with a lantern "Bat" and physiological control. When the flame of a lantern or candle is extinguished or a bright flash, work in the cavity must be stopped.

The range of dangers belonging to the second group is much wider and more diverse.
Artificial landslides and rockfalls. They usually occur when organizing descents into vertical karst cavities and when exploring multi-storey caves. Note that when descending into the mines, at least one person must remain at the entrance to them. This serves as a guarantee against random stones thrown by tourist groups, hunters, shepherds. Dangers arising from the use of unreliable supports. In some cases, there may be a real danger of an unexpected failure of interfloor ceilings made of thin sintered crusts, from under which loose aggregate has been washed out.

Danger of getting lost. In popular literature, it always accompanies the cave explorer. However, in reality, it threatens only the beginner and exists only in the labyrinthine caves of Podolia and Siberia and in the complex multi-storey caves of the Crimea, the Caucasus, and the Sayans. It is easy to avoid it by applying simple labeling rules.

Dangers arising from smoke in caves. Occur with ignorance of the microclimatic and wind conditions of the cavities. In poorly ventilated wells and caves, when using torches, oil lamps and other similar light sources, the smoke cloud does not disperse for a long time. In well-ventilated caves, there is often a danger to other groups in the upper or lower floors, as the smoke cloud is sucked several hundred meters into the depths of the cave. Therefore, you can not make fires in front of the entrance to the cave. When visiting the caves it is necessary to use non-smoking light sources. Dangers associated with the production of various studies. They occur mainly when using high-power ungrounded flash lamps and when transporting explosive scuba compressed air cylinders.

One of the serious dangers of caves is jamming in narrow holes and crevices. Experience shows that the smallest gaps passable for a trained speleologist are 19-22 cm wide. The possibility of passing through such a section is determined not only by its size, but also by the configuration and condition (degree of roughness) of the walls. When passing through narrow sections of the cavity, the most difficult thing is turning and turning, requiring the maximum ability to relax, hold your breath for quite a long time, without stopping muscle efforts.

You should always remember that the hole may turn out to be impassable and the path done will have to be repeated, moving backwards. Here the main danger is rolling up clothes. Low clay passages are also very dangerous. The adhesion of dirty clothes to wet viscous clay can be so strong that the caver will get stuck in the middle of the passage.

Precautions: proper equipment - special clothes that do not wrap when moving in the opposite direction, clearing and widening the passage, observing the correct tactical order for overcoming bottlenecks (stronger build cavers secure themselves in front and behind in case of getting stuck). When overcoming very narrow gaps, it is necessary to remove the upper, and sometimes the lower clothes.

The biggest danger of caving is to remain underground without light. The main security measure is the availability of independent energy sources.
The exploration of caves, deep mines, faults or abysses is one of the most dangerous and difficult activities. One of its varieties, which has arisen relatively recently, is the study of underground communications, the inhabitants of which are diggers. It should be noted that even the usual exploration of simple caves is associated with great dangers (for example, radiation, daughter products of radon deposited in the lungs, the possibility of collapses, etc.).

Speleotourism can be very different in direction.
Excursion and educational tours are held in caves specially equipped for excursions. In such caves, tourists move along specially laid paths or by transport (for example, mini-electric locomotives), they have lighting, the routes are accompanied by qualified guides. Visiting equipped caves does not require special physical training.

Sports speleology involves visiting unequipped, but to some extent studied caves. Such caves are usually safe, and groups of tourists are accompanied by experienced instructors.

Speleotourism of a research orientation is the travel of professional speleologists in order to discover and explore new caves and cave complexes. It is this type of speleology that can be called extreme. It requires special equipment, training and special skills. However, the hardships and dangers of caving and the huge risk pay off with interest. The beauty of underground palaces with stunning beauty of stalactites and stalagmites, the most diverse bizarre creations of nature, fascinates and amazes. There are many unique caves in the world. To name just a few of them: the colossal cave "Grotto of the Giants" in Europe, the "Marble Cave" in Kentucky (USA), Waitomo in New Zealand, New Athos in Abkhazia, Kungurskaya Cave in the Urals, Thousand-Headed Cave in Crimea and hundreds of other amazing