Essential tips to remember when things go wrong
The first thing to remember is not to panic - it always makes things far, far worse underwater.
You should be diving with your buddy near to hand and between you most problems are resolvable. When things go wrong you quickly see the virtue of buddy diving.
Remember to stick close together and to do your buddy checks thoroughly before getting in the water.
Also, know your, and your buddy's limits, and don't dive beyond your comfort zone. It is also crucial to maintain your kit and to get it serviced regularly.
But if something does go wrong here are some handy tips to be familiar with. And make sure you travel with good insurance as your ultimate back-up. DIVE readers get at 20 per cent discount on policies with Holidaysafe Travel Insurance - http://bit.ly/2cg7No3.
1) Ear pain
On descent divers can sometimes feel pain in their ears and are unable to equalise. If this happens you should stop descending as soon as you feel the first pangs. Ascend a metre or so, if the pain disappears, try to equalise and descend again. If the pain returns go over the same process. If you can't equalise and descend without ear pain then return to the surface and end your dive. If you continue to descend when pain occurs it could lead to a perforated ear drum which can stop you from diving for months.
2) Reverse blocks
The most common reverse block occurs when mucus traps some air in your sinus which causes pain when you ascend. It is rare, but if it does happen to you, let your buddy know that you need to ascend slowly. Don't panic, some blocks can take a while to free. If you feel pain, stop and ascend very slowly. You may have to descend a few metres for the air bubble to shrink. Don't force it - the bubble will eventually escape.
You should see a medical professional if you do ascend with a reverse block - it can lead to a painful sinus infection if not treated.
Never dive with blocked sinuses, nor with a heavy cold. You can use mild decongestion drugs - but make sure the effect will last the duration of a dive.
3) Loss of weight
Weight belts can come loose - normally because they haven't been properly fastened or the belt is too small or very worn. Also, it has been known for badly affixed pocket weights in BCDs to slip out. Check your kit and your buddy's before you dive.
If it does happen to you, first dump all the air from your BCD and try to grab hold of something. If you can hold yourself in position it may be possible for you or your buddy to retrieve you weights. If not see if there is a rock you can use as a weight to slow your ascent. If there is nothing suitable and you have to make an uncontrolled ascent, flare your body to maximise drag, make sure all the air is dumped from your jackets and remember to exhale.
4) Running out of air
First calmly switch to an alternate air source - preferably your buddy's and then make a controlled ascent with the usual safety stop. If that isn't possible and your tank is empty, you are going to have to make a controlled ascent as best you can - remember to exhale as you ascend and try to attract the attention of other divers. As you ascend and the ambient pressure decreases more air may be available from your 'empty' tank.
The simplest way to avoid this happening to you is to keep a regular check on your air supply (this should be second nature to you) and to stick close your buddy.
5) Losing your regulator
Remember your training; don't hold your breath, breath out small air bubbles slowly but regularly, move your left arm in a wide circular motion to catch your regulator, replace it in your mouth and purge it before you breath in again. If you are finding it difficult to find your regulator, or feel anxious, grab your octopus to breath from while you search for your regulator.
6) Losing your mask
The other piece of equipment that can easily get knocked off is your mask. Losing your sight underwater can be very disorientating.The best way to prepare for this is to carry a spare in the pocket of your BCD. If you don't have a spare and you can't open your eyes underwater, thus are unable to locate your buddy, just try to remain calm and stay as still as you can; trying not to descend or ascend. Your buddy should come to your aid, either retrieving your mask or holding on to you while you ascend to the surface, completing your safety stop en route.
7) Losing your regulator and mask
It is bad enough when you lose either your regulator or your mask, but losing both at the same time is much worse. If this should happen to you, try to remember your training. Firstly, your priority is to be able to breathe so reach for your alternate air source. Staying calm wait for your buddy to assist you. If you have a spare mask put that on then find your regulator.
Narcosis occurs at different depths for different people and it can be difficult to know when you or your buddy is affected. Symptoms vary and include, but are not limited to, dizziness, ringing in the ears, tingling in the lips, limbs or feet, and inability to read small letter/numbers. If you experience narcosis and are in control enough to realise, ascend slowly to a depth where you no longer feel the affects. If you notice your buddy struggling and suspect they are narked, hold onto them and ascend slowly to a level where they are okay.
9) Not enough air to complete your safety stop
Some boat dive leave a spare tank with regulators at 5m to make sure no one has to cut a safety stop short. Alternatively, you can use your buddy's alternate air source if they have sufficient air. Should you find yourself in the position of not being able to complete your safety stop due to lack of air from any source, once you reach the surface breath pure oxygen if it is available. Do not under any circumstances return underwater with borrowed kit to complete the safety stop. Monitor yourself for symptoms of decompression sickness. If any occur immediately seek treatment.
10) Exceeding your no decompression limit
If you exceed your no decompression limit by more than five minutes you should extend your safety stop to a minimum of 15 minutes. You should not dive for at least 24 hours after you surface. To avoid exceeding your no decompression limit always keep a close eye on your dive computer, especially when you are at depth. Start to ascend when your no decompression limit reaches 10 seconds or less. Keep your dive computer set on the conservative side.
11) Broken O-ring
If you hear a loud explosion underwater the chances are an O-ring has broken. Look around to see if you can locate a mass of bubbles coming from your, or anyone else's, first stage. If it is yours you need to get your buddies attention as quickly as possible as your air will not last long. Take your buddy's octopus as a breathing source and ascend together (don't forget your three-minute safety stop). Other than checking your kit before diving, and getting it serviced regularly, there is not much you can do to prevent an O-ring blowing while diving - thankfully it is extremely rare.
12) Free flowing regulator
If your regulator starts to free-flow the simplest option it to switch to an alternate air source and calmly ascend with your buddy. If you don't carry an independent alternate air source you are probably going to have to use your buddy's octopus. A free-flowing regulator can empty a tank well before your safety stop is completed. You can turn off your cylinder to stop the noisy and distracting free-flow. Most free-flows are caused by poor maintenance - make sure your regulator is regularly serviced.