Sometimes, certain dive students remind me of toddlers. Immersed in an exciting world filled with colorful objects to chase, these divers are easily distracted. On a recent dive, I glanced down at my pressure gauge for just a few moments and when I looked beside me, my diver had vanished! He had managed to jet about fifty feet ahead of me and was now giggling delightedly at a parrotfish. This, I reflected to myself, is the problem when we give dive students fins -- they can actually swim. Sometimes they can swim surprisingly quickly. The novelty of swimming with huge powerful fins can make divers forget that the goal of diving shouldn't be to swim as fast as possible.
Why shouldn't scuba divers race across the reef at top speed? Won't swimming quickly allow divers to cover more ground and see more aquatic life
? Yes and no. While swimming quickly will certainly propel a diver over more reef per a minute, divers who speed through the water breathe more heavily than slow-moving divers because they exert themselves more. An increased air consumption rate
leads to a shorter dive time. The amount of aquatic life a diver sees is proportional to the amount of time he stays underwater not to the distance he covers. In fact, divers who swim quickly tend to pass over interesting smaller creatures such as anemone crabs, blennies, and seahorses
Constant kicking frequently masks major problems, such as poor buoyancy
control or improper weighting. A diver who won't stop kicking frequently can't
stop kicking because he is using his fins to adjust his buoyancy rather than using his buoyancy compensator (BC)
. For example, a diver who is negatively buoyant (sinking) may drop his legs and kick himself upwards to maintain a consistent depth instead of adding air to his BC. This is a terrible habit -- fighting to stay up by kicking is exhausting. Many divers have to force themselves to slow down and occasionally stop all movement before they learn to fine-tune their buoyancy control.
I have also noticed a correlation between rapid swimming and poor situational and buddy awareness
. Using my favorite diving analogy, swimming too quickly is like driving a car at one-hundred miles an hour. It is nearly impossible to enjoy the scenery when you must keep your eyes and your attention focused on the road. Instead of racing through the dive, swim slowly and take time to look at all the amazing details around you. Notice landmarks and references, and check on your buddy once in a while.
Swimming rapidly may also make diving unsafe on a physiological level. During the open water course
, students learn to avoid exercise at depth because it increases the risk of decompression sickness
. A diver who swims hard enough to raise his breathing rate is doing the scuba equivalent of running a marathon underwater. Furthermore, breathing resistance increases underwater in proportion to depth. A diver who increases his breathing rate may not be able to exhale all of the used air from his lungs. This leads to an increase in carbon dioxide
, which can cause a diver to feel starved for air, become dizzy or even fall unconscious! Even a short burst of speed can increase a diver's carbon dioxide levels. Several divers I know have shared stories of chasing fast-moving aquatic life for a photograph, only to become dizzy and lightheaded due to the increased level of carbon dioxide in their systems.
All divers, novice and experienced, should avoiding racing through the water. Swimming too quickly when scuba diving shortens dives, causes divers to overlook interesting aquatic life, masks serious buoyancy problems, distracts them, and leads to physiological issues. Slow down and take it easy underwater -- diving should be relaxing and enjoyable, not exhausting! With great fin power comes great responsibility. Don't abuse your fins!