Manta Divers June, 2011 The Fine Art of Surfacing
The Fine Art of Surfacing
When people question me about diving, they commonly ask, “Aren’t you afraid of getting the bends?” What non-divers don’t know is that it is very easy to prevent decompression sickness by closely monitoring my computer, and making careful ascents. But what makes a careful ascent?
When you think about it, a careful ascent actually starts before the dive. Dive planning should always include ascent criteria. Decide with your buddy when you will ascend. For example, when one of the dive team has 750psi, or at 1 hour bottom time, or when 10 minutes of no-deco time is left. Many times, just because of the topography of the reef, divers will descend to the deepest planned depth and work their way up the reef making essentially a super slow ascent, but what about dives where there is no sloping grade to follow to the shore? For example, what if you are diving one of the many wrecks in Lake Michigan? You descend to the wreck, explore and then ascend back to the waiting boat: a flat profile.
When the divers’ agreed upon criteria is met, the buddies should signal to each other that it is time to start the ascent together. Having a buddy close at hand to offer another air source, or a depth gauge and timer in case of computer failure, can mean the difference between a minor issue and disaster. Remember that as you ascend, the pressure decreases, causing an increase in the volume of the gas in your BC. Inexperienced divers sometimes realize too late that this increased buoyancy can get ahead of them very quickly. A good strategy to remain in control of your ascent is to dump some air from your BC prior to starting to swim up. Have a hand on one of your dump pulls throughout your ascent and be prepared to release air as needed. Watch the ascent rate monitor on your dive computer, if you have one. Remember that the recommended ascent rate is 30ft. per minute and your computer will likely give a visual and/or audible signal if you exceed this rate. Closely monitor your depth as well to be sure that you don’t blow past your safety stop depth.
Safety stops are important because they allow the fastest off-loading of gasses. The fact is that once bubbles form, it takes the body much longer to resorb them, so gradually releasing pressure on gasses dissolved in our bodies and simply exhaling them is always going to take less time than trying to get rid of bubbles once you are at the surface. It is particularly important to be aware of this fact when doing deep dives. While divers should always do a 3 minute safety stop at the end of their dives, if they are doing a deep dive, a deep stop would add a measure of safety. A deep stop is an additional stop on your way to the surface. If, for instance, you dove to 100 ft. to look at a wreck, you should plan to ascend to half that depth, or 50ft. and hang out for 1-2 minutes. After this, ascend in 10 ft. increments and staying for 1 minute at each level, allowing the gas to safely leave your body.
Once all of your deep stops and your 15ft. safety stops are complete, your computer will signal that you can ascend to the surface. Buddy teams give each other the thumbs up and start swimming up. At the same time, look up to avoid any unexpected obstacles or hazards. Again, if you’ve made yourself a little negative prior to starting your final ascent, you will have no trouble stopping yourself if you spot a swarm of sea wasps, or some other diver swims to the boat ladder in front of you. As you break the surface of the water, fully inflate your BC and relax until you are ready to get out.
Following these simple guidelines for ascending should go far to keep you safe from “the bends!”
In other news,
Remember that Advanced Open water is free (except for manuals) with the purchase of a new BC and Regulator.
Our rental clearance is still in full swing, so if you aren’t ready for a new BC and Reg, but would like the security of owning your own gear, why not purchase one of Manta Divers’ gently used set ups?
Don’t hesitate to get your reservations in for Barbados in Jan. 2011. Half of the spots are already sold!
Special thanks to Kathryn Elliott for knitting me my very own flounder. Team Manta is lucky to have in it's membership so many artists, crafters, photgraphers, explorers and of course, scientists!
Finally, if you still need to complete some open water dives, check out the calendar page and get your reservations in. It looks like we are finally getting some warm, summer-like weather, so let's go diving!