The most effective way to descend would be to rely on your rather than using only the BCD to do so. The idea is that the diver should be able to control his buoyancy adequately to be able to stop his descend any time & achieve neutral buoyancy almost immediately. To achieve this do not use the BCD as a depth control device(deflate to descend & inflate to ascend). Think of it only as a compensator device. Rather use your (and sometimes fins) to descend/ascend and when underwater use the BCD to compensate for any loss of buoyancy control i.e excessive positive(deflate BCD) or negative buoyancy(inflate BCD). Follow these steps for a controlled descend…
- Do not dump all the air in the BCD to begin a descend.
- Deflate the BCD incrementally till you float at mask level. Keep full of air. This is neutral buoyancy at surface.
- When ready to descend & with regulator in the mouth begin to exhale air from slowly & fully. Be patient is will take few seconds & when at end of exhalation you will notice a descend happening. In case unable to descend, deflate BCD a wee bit more & repeat the above process.
- After descent starts you will reach a point when you cannot control your buoyancy with your . At this point you will sink even when you inhale & you are no more neutrally buoyant(being neutrally buoyant would mean you would rise slightly upon inhalation). Inflate the BCD a little bit and this descend or ascent upon inhalation will stop. This will the point of neutral buoyancy below surface.
- If the required depth is not reached, use your again to descend by exhaling fully and not by using your BCD. Use the BCD only to reestablish neutral buoyancy at end of exhalation.
- The above process of controlled descent initially will be time consuming, but with practice it will become effective & efficient. It is a much better way for a controlled descent rather than purging all the air from then BCD at once at the beginning of the dive.
The method of controlled descent has few advantages – the diver controls his descend which proves helpful in case of equalization problems. With this method the diver is able to reach the depth without hitting the bottom and avoid damaging the & . Wastage of air while purging from BCD is minimized. With controlled descent a diver will be better able to help his buddies in case of any need.