Dives with mandatory decompression are safer than repetitive dives, each of which takes place at the no-decompression limit. So don't be afraid of decompression - in the end, it's also just a slow ascent with small "pauses". Even the smallest changes have a big effect. With the following knowledge, prepared by our content partner underwater, you can make your dives much safer.
Plenty of movement Exercise instead of tension is the best recipe against cramping a muscle. When clinging to a rope or reef hook, the permanently contracted muscle squeezes the vessels through which it should be supplied with nutrients and cleared of inert gases.
Safety stops It is now common and taught that a safety stop should be made at five meters for three minutes duration before surfacing, even if diving within the no-decompression limit. In addition, a stop of one minute at half the maximum depth has recently been recommended. During the safety stop, excessive effort should be avoided. The same applies to stops that must be made as part of decompression.
Horizontal water position The horizontal water position prevents a pressure gradient in the lungs and thus puts less strain on the respiratory muscles, making it easier to inhale and exhale and thus providing more lung volume for gas exchange. Spar breathing is one of the mistakes many divers make. Especially when the gas supply is running low, many divers tend to breathe shallowly. However, just the opposite is necessary. Deep breathing promotes gas exchange because more lung capacity is used.
Gas break When deco'ing at six meters, it has proven useful not to breathe pure oxygen for the entire deco phase, but to alternate between pure oxygen and a gas with reduced oxygen content. This gas break means that for longer deco times at six meters, after twelve minutes of pure oxygen breathing, you switch to a reduced oxygen gas mix for six minutes. Since our lungs are sensitive to high oxygen partial pressure, causing the alveoli to swell (reducing oxygen delivery to the blood), too much oxygen impedes gas exchange between the blood and lungs.
Attention in mountain diving In addition to physical adaptation (exposure to cold and "thinner" breathing air), decompression levels shift depending on altitude. Since the pressure differences are even greater here, the risk of bubble formation also increases. The computer must therefore be set accordingly. Depending on the definition, altitudes from 400 to 700 meters are considered mountain dives.
Avoiding chilling Avoiding cooling down prevents a typical protective reaction of our body: When freezing, it tends to supply the vital organs with more blood and the "unimportant" body regions with correspondingly less blood. As a result, the inert gases are not removed to the extent calculated by the dive computer's decompression model, and a decompression accident can occur. Dressing warmly and moderate exercise during the dive-out phase are the best ways to keep freezing to a minimum.
Drink enough before diving This ensures good viscosity of the blood. Thus, even the smallest capillaries can be well "flushed". If you drink little, you risk reducing the blood volume and thus also the cardiac output. It is best to start drinking fluids hours before the dive and not just ten minutes before descending.
Helium as breathing gas When diving with nitrogen, the fat solubility causes the inert gas to accumulate in the fatty cell walls of the brain, which swell at the same time. With helium, exactly the opposite happens: shrinkage of the membranes leads to uncontrollable impulse transfers. To avoid this, a residual nitrogen is required in the breathing gas to counteract the shrinkage - this is how trimix is created, but its real advantages are not in terms of decompression: Helium saturates in the body three times as fast as nitrogen. Because of the relatively short bottom times, this phenomenon is more predominant during saturation than during desaturation. In the initial phase of a dive, helium takes more time to leave the body compared to nitrogen. Only when the bottom time becomes longer than 30 minutes does helium leave the body faster than nitrogen, resulting in a shortened decompression time. The problem is that it leads to microbubble formation much faster than compressed air. For this reason, the ascent rate of ten meters per minute must not be exceeded, even at great depths. For further safety, depth stops of one to two minutes are scheduled.
Fitness Keeping fit automatically strengthens the cardiovascular system, which results in slower fatigue during physical exertion. This also leads to a better blood supply to the capillary system and thus to a better removal of inert gases. If you have a cold, you should refrain from deco diving. Here, the immune system is already working at full speed and every foreign body is attacked. If even the smallest bubbles develop, they are isolated and encapsulated (wrapped). These plugs pose a great danger and, in the worst case, can lead to vascular blockages.