As a new scuba diver, once you have completed your initial training and you start enjoying more fun dives. You may begin to notice that other divers seem to somehow enjoy longer dive times, or that as part of a group you are the first signalling to the DM that you are low on air. It is often not a nice feeling, especially if you are causing other to end their dives early. It is also a common reason why more experienced divers don’t want to buddy with newbies.
Firstly, don’t beat yourself up about it, and especially for safety’s sake don’t try to hide your real pressure when asked. The reality is everyone consumes air at different rates, smaller divers use less energy, and others may have have a slower metabolism, be fitter, healthier, less stressed and so on. As you gain experience and progress further in diving you should become more aware of your SCR (Surface Consumption Rate) or SAC (Surface Air Consumption), and what effects various conditions have on it, but that is for another article.
become more aware of your SCR (Surface Consumption Rate) or SAC (Surface Air Consumption)
Now, the good thing is with some understanding and following a few of the tips below you will be able to reduce your air consumptions and get longer dives. You may not ever be the best, but a gradual improvement will lead to longer dives and greater enjoyment of scuba diving.
A few simple places to start include leaks, streamlining, trim, weighting and buoyancy.
These are easy to spot and sometimes may indicate a more serious problem ahead. Most common tends to be a leak at the tank O-ring, often times rental tanks may have old or damaged o-rings. When assembling your gear carefully check the o-ring for damage and cracks. It is also useful to carry a o-ring pick and spare o-rings in your save-a-dive-kit. You may also find you get a freeflow when giant striding into the water from your octo, if you do try to de-tune it slightly.
Streamlining, Trim, Weighting and Buoyancy
As a diver you want to achieve the most streamlined shape in the water as possible. This will allow you to glide or propel yourself through the water with the minimum of effort, use the least amount of energy and consume less air.
Check your gear is streamlined, don’t wear a BCD 2 sizes too large, don’t use a BCD with +20kg of lift in warm Taiwan waters, you simply don’t need that much lift, possibly upgrade from a jacket style BCD to a back inflate, don’t take equipment along you are not going to need, don’t leave items dangling, make sure items you do carry are stowed in a pocket or clipped tightly to your body.These are all related, but what you want to try to achieve
Adjust your trim. Often you will see new divers almost appearing to walk horizontally or doggy paddling though the water at 45 degree, this is very in-efficient. Your body should be horizontal in the water so your body and legs will follow though the hole made by your head and shoulders so you disturb the least amount of water. To Help move a little weight from your weight belt or quick release pocket up onto your shoulder or tank band, this will distribute and help balance you. However remember this weight becomes non-ditchable so only move a little.
each extra kg of weight accounts for 1 extra liter of air you need to add to your BCD to float which you then have to push through the water
Its important to reduce your weight and achieve neutral buoyancy. If you are overweighted at depth you need to add large amounts of air to your BCD to achieve neutral buoyancy. This air increases your BCD size, each extra kg of weight accounts for 1 extra liter of air you need to add to your BCD to float which you then have to push through the water. Also if you are neutral buoyant you don’t need to expel any extra energy to float and maintain your depth.
consider taking the (PPB) Peak Performance Buoyancy course, this will help you get everything sorted out
If you are having trouble with trim, weighting and buoyancy contact your instructor and consider taking the (PPB) Peak Performance Buoyancy course, this will help you get everything sorted out.
Next you can start to look at yourself and ways you can improve your breathing and efficiency of air consumption.
Stress raises your heart rate and your breathing rate, being relaxed before and during the dive will slow your breathing. Initially diving can be stressful, however the more you dive the more relaxed you will become, other tips include being well rested, sleeping early and especially no big partying the night before.
When diving, try to arrive at the boat or dive site early so you can slowly and calmly prepare for your dive. Running around at the last minute will raise your heart rate and breathing. If you are doing a shore dive, after the surface swim always stop for a few moments to catch your breath and lower your heart rate before descending, it will make a difference in the early part of the dive.
Long tern you can also get in shape, if you huff and puff after walking up a flight of stairs the same will be true when diving. Your faster breathing rate is wasting air. The fitter you are the slower your heart rate will be and the slower you will breath. You don’t need to build muscle or anything, frequent cardio workouts are the best, your body will thank you too..
Dive Slow and Steady
Don’t over exert yourself, it is not a race, take it slow and steady. Did you realize that doubling your speed takes 4 times more energy, halving your speed uses just a quarter. When moving don’t constantly kick, try to kick – glide – kick – glide. Look at learning a more efficient kick like the frog kick.
Did you realize that doubling your speed takes 4 times more energy, halving your speed uses just a quarter
Or if you know you consume air faster than others, try to swim shallow, by this I mean if swimming along a wall keep a few meters above your buddy, this way due to lower water pressure and the way a regulator works, you will consume less air. On a 20m dive swimming 2m shallower than your buddy will translate to just over 7% saving all things being equal.
Breath Deep and Slow
Try to control your breathing, breath slow and deep. Breathing fast uses more energy, and increases the deeper you go. Take a long slow breath in, followed by a slow exhale.
Additionally by breathing slowly more air will get to your lungs and have more time to be absorbed by the bloodstream leading to a more efficient breath. If you breath fast and shallow less of the ‘used’ air is expelled from your lungs and replaced with ‘fresh’ air when you breath, you then have to take another breath quickly meaning most of your oxygen in your air supply is being vented.
Breathing is triggered by a build up of CO2 not a lack of oxygen.
Exhaling fully also expels as much of the CO2 as possible, allowing it to be replaced with fresh air. Breathing is triggered by a build up of CO2 not a lack of oxygen.
Last of all, as much as is possible, try to forget about it, relax and enjoy yourself I mean your are diving for the pleasure it brings you. Keep working at it and as you dive more your air consumption will improve over time.
Good Luck, Have Fun!