Swimming in turbulent rivers without using floating equipment is very dangerous and should be avoided as much as possible. If the situation is urgent and there is no other choice, please strictly follow the following principles： ###1. Risk assessment (must be implemented first) 1. **Absolutely contraindicated** - Single action (must have at least 2 companions) -The depth of water exceeds the waist (it is recommended not to exceed the middle thigh) -The water temperature is below 15℃ (the risk of temperature loss increases sharply) -Visually measured flow rate exceeds 3 meters per second (branch throwing test is available) 2. **Danger signal** ️️The river suddenly narrows (the water flow accelerates) ️️Continuous whirlpools appear on the water surface (there may be reefs) ️️There are waterfalls or cliffs downstream (fatal hidden dangers) ###2. Choose the best crossing point 1. **Topographic features** ✅The river is curved in an "S" shape on the outside (the water flow is slower) 浅Shallow areas with a width of more than 50 meters on the water surface ✅The bottom of the river is a whole rock bed instead of pebbles (high friction) 2. **Reference positioning** ↪Look for obvious landmarks on the other side (avoid being deflected by the current) ↪ Choose the location where there are boulders upstream to form a backwater area ###3. Professional river crossing skills 1. **Three-point support method** - Three people team up to form a triangular formation -The strongest is located on the upstream side to resist the flow of water -The arms buckle each other's shoulders to form a human chain 2. **Travel at countercurrent angle** -Keep the body at an angle of 45° from the water flow -Only one foot is allowed to leave the ground each time you move -Use river bottom sand and gravel to increase friction 3. **Emergency self-rescue posture** 🆘Take the supine position immediately when in distress (nose-ear alignment technique) Keep your legs facing downstream as a buffer 🆘 Wrap important items with clothing to increase the counterweight ###4. Advanced hydrological judgment 1. **Stratification characteristics of water flow** -The fastest surface flow rate (the flow rate at a depth of 0.5 meters is about 60% of the surface) -Use the backwash current at the bottom of the river to save physical strength (common behind boulders) 2. **Eddy current recognition** ️Small diameter whirlpool (<1 meter) Can be forcibly broken through ️The whirlpool needs to escape along the tangent direction ###5. Post-mortem treatment 1. Check your body temperature immediately (first aid is required if your core body temperature is below 35℃) 2. Treat parasites in water (rinse the body with hot water above 60℃) 3. Check the sealing of the equipment (electronic products need to be dried for 72 hours) ️️ Important note: According to data from the International Association of Field Medicine, the mortality rate of untrained people trying to cross the rapids is as high as 37%. It is recommended to bring at least 15 meters of umbrella rope (550 pounds) to make a temporary protection system, or wait for the water flow to slow down to less than 1.5 meters per second (the speed can be measured by floating objects) before acting.