When the water is just a little too cold to get wet a good drysuit undersuit is important. But it’s not the only way to keep warm on and between you dives? If your teeth are chattering after every dive then we have few tips for you that might just help keep you warm while we wait for the summer!
OK before we look at the tips for keeping nice and warm here are some basics on drysuit under suits if this is new to you.
Unlike a wet suit that keeps you warm by trapping a layer of water that your body heats, a dry suit traps a layer of air. Air is about 25 times more efficient than water as an insulator so you can, in theory at least, be warmer for longer in a dry suit than a wet suit. Plus in a wetsuit there is some ‘flushing’ of the water resulting a gradual cooling but the drysuit is sealed (mostly).
However a drysuit is not designed to offer thermal protection on its own. Modern compressed neoprene drysuits have some inherent thermal protection, so don’t require such thick undersuits whereas drysuits made from thinner materials such trilaminate or membrane have no thermal protection and a higher rate of heat conduction so require a thicker undersuit.
Just like your favorite fleece or jacket an undersuit is needed to provide thermal protection by trapping air close to the body and maintaining body temperature during the dive. Modern drysuit undersuits can range from simple micro fleece type garments to those made from ‘technical’ materials and undersuits suits with anti-compression panels or even built in heating.
As a general rule a neoprene drysuit will only need a lighter fleece undersuit, typically around a 100gram to 150gram weight in a two piece configuration. A membrane suit will need 200gram with up to 400gram for cold water. It’s also worth noting that the less trapped air an under suit needs to keep you warm the better. This is due to the inherent problem of having a large amount of trapped air in the drysuit undersuit . This is why an under suit that is based on a ‘lofting’ material (similar to a sleeping bag) is in some circumstances not as good a choice as multi layered Thinsulate suit as it’s easier to dump. A one piece undersuit is also a good choice with a membrane suit as it prevents getting a cold spot on your lower back!
So now you have the right thickness and type of undersuit what else can you do to keep warm during and after dives? Here are our tips.
1) Have a proper breakfast
A nice as it is a bacon roll just isn’t the fuel that you need. If you are diving in colder conditions slow release carbohydrates are the divers best friend. So that’s porridge oats and bananas or peanut butter and brown toast (or both!) This will give you the fuel to keep your body warm during and after a dive.
2) Invest in a P-valve
If you are able to drink plenty of warm drinks and remain comfortable (and not cross legged) it will make a huge difference. Holding back on fluid intake when it’s hot is not a good idea and just as bad when it’s cold. Being cold and needing to urinate is just about the most miserable feeling there is. A modest investment in a P valve will solve that.
3) Don’t forget your feet, head and hands in and out of the water!
Don’t cut corners when it comes to your extremities. Invest in good booties rather than just thick socks, use a 9mm cold water hood and the colder months either semi dry or a dry glove system. Although a proper look at dry gloves is a blog on it’s own suffice to say the difference keeping your hands warm makes to your whole body is unbelievable. Heat loss from your head is huge, and if you are wet after a dive it will continue to drain heat from you. As soon as you get out of the water put a beanie hat on! Also some nice gloves or mittens will help your hands stay warm as well in between dives.
So there you have my top tips, enjoy and stay warm!