We may be surrounded by water while diving, we must remember to drink it as well. It may seem a little counterintuitive, compared to other sports, but staying hydrated while scuba diving is actually as important — if not more — than it is in other sports. Unlike while participating in terrestrial sports, we don’t sweat when we dive. So how do we dehydrate?
Sucking out the water
We primarily lose water while diving through something as basic as breathing. Every time we inhale and exhale on land, we lose a little bit of water. But when we dive, we’re breathing extremely dry air compared to anything we find in the atmosphere. This is deliberate, as the compressors that fill dive tanks are designed to remove almost all the moisture from the air they use.
Moisture in the tanks can cause condensation, which, in turn, can cause the inside of the tank to corrode. But as a consequence of breathing such dry air, we lose quite a bit of water from our bodies while we dive. And just because we don’t sweat when we dive (at least not unless we’re diving in drysuits) we still lose water from the physical activity. Exertion increases our metabolism, and our metabolic processes are actually the main way our bodies use liquids.
Consequences of dehydration
Most people who have been dehydrated will know that it’s unpleasant. Symptoms such as a dry mouth, headache, and general sluggishness are not very conducive to scuba diving. A more severe consequence means that as we dehydrate, our blood thickens to some degree. This, in turn, makes it less efficient at transporting fresh oxygen to our cells. This is why being well hydrated can enhance your athletic performance. Thickened blood is also less efficient at transporting metabolic byproducts from our cells to our lungs, where they are expelled from the body. This is important, as this is how the nitrogen that we release as we rise is released from the body. Your dehydrated body is less efficient at getting rid of nitrogen, making decompression illness more likely.
Luckily, staying well hydrated is as easy as drinking a glass of water. Literally. Generally speaking, there’s no need for sports drinks or electrolyte solutions — simply eating a normal, healthy diet combined with a good intake of water is plenty. The trick is to make sure you’re getting enough before you get thirsty. Drink before you’re parched.
When you’re diving, try to drink enough water so that you’re never really thirsty, but not so much that you must urinate all the time. Your urine should be clear, and without noticeable odor. If you’re diving in tropical climates, you should drink quite a bit more water than you’re used to. About ½-gallon per day is a good starting point for most. And although diving in warm climates requires more water, the extra exertion, even in cold climates, means diving does dehydrate you to some extent. So drink up, divers.