Written by DAN Staff
In the Northern Hemisphere, temperatures are dropping as winter approaches and for many locations that means it’s time for dry suit diving courses to start. Dry suits are excellent exposure protection for comfort and safety. They provide warmth, redundant buoyancy and the ability to get in the water all year long, but they come with some specific safety concerns. Brush up on the hazards so you can better prepare your students for cool water diving.
Tight wrist and neck seals aren’t just uncomfortable, they can cause real problems for divers. Neck and wrist seals should fit snugly but should not restrict blood flow. Wrist seals that are too tight can cause pain in the fingers and hands as well as numbness, tingling and loss of dexterity. They can also increase the risk of a cold injury due to decreased feeling and blood flow.
Tight neck seals have the potential to induce carotid sinus reflex. This reflex slows the diver’s heartbeat and the flow of blood to the brain and can make the diver feel dizzy or lightheaded or lose consciousness if left unchecked. You’ll size your student’s wrist and neck seals during a class, but double check them when you get to the dive site. Changes in temperature, position or stress can cause minor swelling and make a seal tight enough to cause a problem. Make sure seals are trimmed and stretched to the appropriate size before getting in the water.
There are many causes of diving-related skin conditions, and some of them have the potential to mask more serious concerns. This is the case with many dry suit-related dermatological issues. New divers who fail to add gas to their dry suits as they descend and experience a squeeze may get rashes, chafing or bruises as a result. While uncomfortable, these typically have no lasting ill effects. These bruises can be dramatic, however, and sometimes resemble cutaneous DCS, also known as skin bends. If one of your students appears to have bruises after a dry suit dive, always consider the possibility of DCS and respond based on the apparent symptoms (or lack thereof). Early recognition of skin bends is important and can significantly increase the likelihood of a positive outcome for an injured diver.
Urination systems are not common in many dry suits, especially rental suits, because of hygiene concerns. However, if your student divers own suits with urination systems, it’s a good idea to teach them how to properly use the system. Pneumaturia (the passage of air during urination), urogenital infections and catheter squeeze can be caused by improper equalization or maintenance of these systems. Covering system-specific equalization, using balanced systems with one-way check valves to prevent water ingress, and covering thorough and regular cleanings as part of hygienic equipment use are critical parts of instruction.