Diving

How to Make Your Movement Underwater More Energy-Efficient

The duration of your dive is limited by your own rate of air consumption, which in turn depends on how much energy you expend. Good finning technique, buoyancy control, and a streamlined profile will all make your movement underwater more energy-efficient.

Efficient Propulsion

Your movement through the water should be driven and controlled by your legs. If you watch experienced divers, you will notice that they use their arms very little, and move effortlessly through the water, saving energy, minimizing air consumption, and avoiding damage to reel’s and the marine environment.

Swimming with fins should be an extremely efficient way of propelling yourself through the water, but many divers are let down by a poor finning technique. There are several different strokes you can use, but all should be carried out with strong, rhythmic movements, fully extending the leg (or legs) with each kick. Uncontrolled thrashing and incomplete kicks will simply waste energy. It is worth asking your buddy to give you feedback on your technique even to photograph or film you. You may be surprised at the results.

Scuba diving is not a race, and the faster you go, the less you see. Learning to pace yourself and move at a leisurely speed will help you to relax, and a relaxed diver is an aware, efficient, and safe one.

Profile and Buoyancy

To achieve the most streamlined (and therefore most energy-efficient) swimming position, you should be almost horizontal in the water. Your hips will be slightly lower than your upper body due to that area being weighted. During a dive, you should look forward and downward most of the time raising your head too much will lift your upper body and make your profile less streamlined.

Carrying the correct amount of weight is important. Being overweighted will drag your hips and lower body downward. Swimming will then require greater effort due to your unnatural angle in the water, which will produce increased drag. You can improve your profile by repositioning the weights in your BC, or refining your weight requirements.

Achieving neutral buoyancy is the key to maintaining a good dive profile with ease, and also increases your efficiency. If you are positively buoyant, you will be constantly swimming downward; if negatively buoyant, you will have to swim upward all the time or crawl along the bottom – all of which require more effort than horizontal, neutrally buoyant, swimming.

Descending and Scuba Diving – Tips and Advice

Descending to the seabed is always an exciting experience, but while you may want to get there quickly, you must always descend in a controlled manner. The method you use will depends partly on the site and prevailing conditions, and partly on your own preferences.

Making Your Descent

Having met up with your dive buddy in the water, follow the preparatory steps below. If you find that you do not sink, cheek that no air remains in your BC (and drysuit, if applicable). If the problem persists, you probably do not have sufficient weight on your belt, and should return to the boat or the shore to get some more. It is a good idea to note how much weight you need each time you try a different equipment configuration record the details in your logbook for reference.

At a depth of 10ft (3 m) you should carry out a bubble check. This involves briefly stopping so that you and your buddy can check each other’s equipment for signs of air leaks for example, from an incorrectly fitted hose. This will allow you to return to the surface to resolve the issue before you resume the dive. By fixing minor problems now, you may avoid bigger problems during the dive that could lead to an emergency.

As you descend, you will feel pressure in your ears. Release this regularly by swallowing or holding your nose and blowing against the closed nostrils – a process called “equalization” or “ear-clearing”. If you feel you art-descending too fast, allow a little air into your BC. Your mask will also start to press on your lace; relieve this by exhaling gently through your nose. If you are wearing a drysuit, you will feel the water pressing it against your body, base this by letting air into the suit, but not so much that it alters your buoyancy too greatly and remember to release it again on ascent.

1. Meet up with your buddy on the surface, well clear of any boat cover. If using a snorkel, remove it, and switch to breathing from primary regulators.

2. Give an OK signal to each other when ready to begin the dive. If using a “buddy line” to link yourselves together (useful when one buddy is a novice), ensure now that you are both attached.

3. The “down” signal confirms your intention J descend immediately. If your buddy is a nervous, reassure them by holding their hand and helping them to descend.

4. Both you and your buddy should deflate your BCs and exhale together, so that you become negatively buoyant and start to sink simultaneously. If you have a problem sinking, address it now.

The Importance of Scuba Dive Buddy Check

Diving with a partner (or buddy) means that there is someone to help if you encounter problems underwater. For the system to work properly, however, you and your buddy need to conduct your own briefing before a dive and check that all equipment is functioning properly.

Making Buddy Checks

Just before the start of the dive, get together with your buddy and assemble your gear and put it on. There is no particular order in which to do this, but most divers find that to avoid overlooking anything, it is useful to develop a routine. When you are both suited up and before either of you enter the water, you should carry out a buddy check-sit or stand next to your buddy and carefully check each other’s gear, following the sequence shown below. Do not be tempted to rush these vital checks-you may regret it later. They ensure that you know how each other’s gear is assembled, how it works, and that it is functioning. They also serve as a double-check that neither of you has overlooked anything before you dive.

1. Check BCs so that you and your buddy know where each other’s inflation and deflation points are, and ensure that they are working. Do the same for drysuits, if worn.

2. Check that weights are present and securely fastened. You and your buddy must be especially aware of how each other’s weights are released, in case either diver is incapacitated.

3. Check harness is secure and note where, on your buddy’s kit, key fastening points and harness release clips are located, and how they are operated.

4. Check air contents gauges and breathe from your regulators to check they are working. Test each other’s octopus second stage.

5. Ready to dive? Give each other a last once-over to establish who is carrying any miscellaneous pieces of gear, such as reels and slates, and where they are fastened. When you are ready to dive, make a final OK signal.

Buddy Briefing

Suiting up provides a good opportunity to talk over a dive plan with your buddy. Ensure first that you are both agreed, as a pair, on the aim and course of the dive, your entry and exit points, and your predicted maximum depth and time for the dive. Check that you both have the required amount of air for your plan (including a reserve for emergencies). Agree on who will lead the dive and on whether you will dive to the left or right of your buddy. Decide on all communication signals, including how and when you will signal for the end of the dive, and on what you will do if you become separated. Once you have agreed a plan, stick to it unless it becomes impossible to do so. If circumstances change during the dive, use hand signals to discuss how, as a pair, you are going to modify the dive.

Preventing Fogging

Mask fogging is a very common inconvenience, and is caused by oils on the mask’s lens allowing moisture to bead. The traditional way to prevent fogging is to rub saliva onto the inside of the lens glass, then lightly rinse clear, before putting on the mask for a dive. Anti-fogging sprays are also available.