An important part of dive planning is deciding how and when to ascend, and provided all goes well on a dive, you’ll be sticking to that plan. In some cases, however, an emergency ascent, in which neutral buoyancy and slow, normal swimming techniques may have to be abandoned, becomes necessary. Whether this happens due to an equipment failure, a frightening encounter with marine life, an emergency with another diver, or an out of air situation, the possibility of an emergency ascent is something that should never be far from your thoughts.
Unassisted Emergency Ascents
If you have to make it to the surface without the aid of a buddy, you’ll be making an unassisted emergency ascent; in some ways, this is a little easier than an assisted ascent. First, try to signal your buddy so he or she knows you’re going up. Ensuring you maintain control of your BCD, holding the inflator / deflator, place your other hand above your head in case of obstructions, and keep looking up and around as you make your way up. Try to exhale continuously to prevent air in the lungs from over-expanding as you ascend, even if you are out of air. Your lungs should feel as if they are half full. Keep your second stage in your mouth, and do not exhale too forcefully.
Assisted Emergency Ascents
When you perform a buoyant ascent, or you are aided by your buddy during an emergency ascent, it is considered to be an assisted ascent. If possible, ensure you maintain control of your BCD, holding the inflator / deflator, and be cautious of obstructions; one of you should have a hand up. Both of you should be looking up and around if possible. Remember to keep exhaling, even if you are out of air, keeping your lung volume at about half if possible. Ensure you both keep second stages in your mouths unless buddy breathing, and don’t expend too much energy on the exhale.
In both cases, remember that you should try to ascend no faster than sixty feet per minute, and remember that your BCD is going to be expanding as you ascend. If you were out of air on the bottom, you may be able to get a couple of breaths out of your tank once you get a bit closer to the surface since the air inside it will expand as well. If you start to feel euphoric or begin to black out, make yourself buoyant and get to the surface. DCS is a real possibility here, but it beats the alternative. Once on the surface, rest and try to calm yourself while focusing on breathing, and signal for pickup if needed.
By practicing proper techniques prior to every dive, and by discussing emergency protocols as a normal part of each dive, you and your buddy can mitigate panic, giving both of you a better chance of arriving back at the surface relatively unscathed. Remember, even if you do not feel any immediate symptoms of decompression sickness right after ascending, they can show up after the fact. Knowing the signs and symptoms of DCS can prevent needless suffering, so be sure to monitor yourself and your buddy carefully if an emergency ascent was necessary.