Why dry suit?
Cold water leads heat away from your body up to 25 times faster than cold air. This means that without the right equipment we would not be able to swim in cold water for very long. Luckily a good dry suit enables us to comfortable dive and snorkel even in extremely cold water. With a good dry suit and the right undergarment we are able to stay in cold water for many hours if necessary.
What is a dry suit?
A dry suit looks a bit like a thick wetsuit, but the main difference is that it has tight seals for your neck and your wrists to keep the water out. The seals can be made of latex, silicone or neoprene. The seals have to be tight enough to keep the water out. The dry suit also comes with attached boots to keep your feet dry.
The rental dry suits that we are using here at Scuba Iceland are made of neoprene. Neoprene suits are the warmest and most durable type of dry suits on the market. Perfect for Icelandic conditions! There are three different types of neoprene: crushed, compressed and regular. Compressed neoprene is the most common type, and can be found in suits from many different manufacturers. With a neoprene dry suit you need less undergarment, as the neoprene in itself provides insulation. A neoprene suit is very buoyant, and require more weight than other dry suits.
Neoprene dry suit
This type of dry suit is made of three layers of durable material laminated together. It is a light weight suit, and less buoyant compared to neoprene. It does not provide much insulation and therefore requires a heavier undergarment. The material in a trilaminate suit will not affect the buoyancy much as you are descending or ascending, as it does not compress in the same way as a neoprene dry suit. This type of dry suit can be used both for recreational and technical diving. It is less popular in commercial diving as it is not as durable as other materials like rubber or neoprene.
What to wear under a dry suit?
What to wear under the dry suit depends on the water temperature. The benefit of a dry suit is that it can be used with just a thin base layer underneath if the water is not that cold, or it can be used together with many thick layers underneath to keep you warm even in the coldest water. See recommendation below:
For water no colder than 15 degrees C: A thin thermal baselayer in fleece or wool (long underwear)
For water 15-10 degrees C: Dual base layers in fleece or wool. Wool socks
For water colder than 10 degrees C: Base layer in fleece or wool plus under suit. Wool socks
Tips for your first dry suit dive:
When diving in a drysuit for the first time you will notice that it’s a bit tricky to control your bouyancy. This is because the dry suit has a big impact on bouyancy, and you can use the dry suit to control your bouyancy, along with your regular BCD.
Most dry suits have an inlet valve located on the chest, and an outlet valve on the left shoulder. Similar to your BCD you simply add gas to your dry suit to increase bouyancy by pressing the inlet chest valve, and let gas out to decrease bouyancy through raising your outlet shoulder valve.
Inflation valve on the chest
Deflation valve left shoulder
If you have already done a little bit of research on dry suit diving you have probably come across the phenomena of floaty feet. As you know, gas will always travel to the highest point under water, as a result of the pressure difference. When diving in a dry suit, your body will be surrounded by gas, which will travel around in your suit when you move your body.
When lifting your feet higher than the rest of your body, the gas will automaticly end up inside the boots of your dry suit, as this will now be the highest point. This will make your feet more bouyant than the rest of your body and make them feel ”floaty”. During your dry suit course you will get to practise how to avoid this from happening, and also practise how to recover from a potential ”upside down” position.
When descending on your dive the gas in your dry suit will compress as a result of the surounding water pressure. The deeper you go the more the gas will compress. You can feel that your suit is getting tighter and tigher the deeper you go. When reaching a depth of only 10 meters a suit squeeze can get painful.
Luckily there is a very easy way to avoid suit squeeze completely. The only thing you have to do is to equailise your dry suit by simply adding a bit of gas to the suit as you descend. When done correctly, you wont get any squeeze, even when diving very deep.
Neoprene suit with a suit squeeze