Cold Water Considerations

cold-water-considerations

Chances are that you may have gotten into scuba diving while on holiday in some tropical location. You may have fallen in love with diving, but the only spots near you might seem uninvitingly cold. Well with the right planning considerations, a cold water dive can be just as exciting and enjoyable as a dive on the Great Barrier Reef. Here are some simple tips for warm water divers who are interested in bringing their holiday passion home with them.

1) Get ready for the shock
If you have only ever been diving in warmer waters then you are in for a shock the first time you enter cold water. Some people feel they cannot breathe at first, but don’t worry, this will pass soon. It is because of the Mammalian Diving Reflex; a natural response when a person’s head is submerged in cold water. A good way to prepare yourself for the dive is to spend a few minutes on the surface before the dive, breathing through either your regulator or snorkel. Usually this feeling of breathlessness will pass in only a few seconds, but it is best to give yourself a couple of minutes so you can allow yourself to get completely comfortable.

2) Prepare for a flooded mask
If you are an experienced diver then you probably have no issues clearing your mask, but be prepared for the first time it floods with cold water. Because our mask helps keep our nose area a little drier than the rest of our body, it can be a real shock when water enters, and exhaling to clear it can become very difficult. Again, this is the Mammalian Diving Reflex kicking in, and you must learn to deal with the initial shock of cold water around the face. When you start cold water diving, it is essential that you practice mask remove and replace a few times, even if you are an experienced diver. It won’t take many times for you to learn how to handle the shock, and it is better than unexpectedly panicking while at depth.

3) Use the correct equipment
It is not only exposure protection you need to think about while diving in cold water, you also need to ensure your regulator is approved for use in cold water diving. As gas expands, it also cools rapidly. This combined with the chilly waters may lead to parts of the first stage to freeze up, causing a free flow. A cold water regulator should be environmentally sealed to prevent this from happening. Even with an environmental seal, a regulator can still free flow, so extra precautions should be taken to prevent this from happening, such as not inflating the BCD while inhaling, so not too much demand is placed on the first stage.

4) Gearing up in the right order
If you have never been diving in cold water, you will probably have never needed to wear hoods, gloves or drysuits. Once your gloves are on, it will be almost impossible to make micro adjustments to your equipment, such as removing or attaching arm mounted gauges, or tucking your mask skirt into your hood. It will take more time to get everything on, and because of the thickness of all the layers you will be wearing, it will more difficult to move around.

5) You will use more gas
When we dive in cold water, all the extra layers and weight create more drag in the water, which means it takes more effort, and we need to use more gas. When we become cold, we burn more calories, which means we need to use more oxygen, so again, our breathing rate will increase. Although we can’t really do anything about the extra drag created from the essential pieces of equipment, we can try our best to not get cold underwater. Using exposure suits that will keep you properly insulated will stop your air consumption from rising too much.

6) You will need a lot more weight
Cold water divers may use thicker, semi-dry wetsuits, or even drysuits. Hoods are essential, as are gloves. With all these extra buoyant suits, you will need a lot more weight than you would if diving in a 3mm suit in the Caribbean. When you first start diving in cold water, you may find that it is difficult to fully exhale (due to the shock of the cold water around your face), which means getting under may be a challenge. Doing a buoyancy check before your first cold water dive is essential, otherwise you may struggle to get below the surface. You may need nearly 10 kilos or more, so it might be a good idea to spread the weight around. That much weight on a weight belt will probably be uncomfortable, and overloading integrated pockets may cause them to fail. Plus if you suddenly lose one of the weight systems, you will not shoot to the surface like a firework.

7) Think about time spent out of the water
Just because the water is cold, it doesn’t mean air above the surface is. You may be spending quite a lot of time on a boat getting to a dive site in 20 plus degrees Celsius, which will be very uncomfortable in a drysuit. Water is essential to help prevent you from overheating, and keeping out of the sun will help keep you cool. On the other hand, the air temperature may be very cold, so a thermos flask full of tea, coffee or soup is always nice after a cold dive.

‘Cold Water Considerations’ was written by Mike

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