Is Neoprene Warm?
Wes Severson May 6th, 2020 Posted In: Articles
Is Neoprene Warm?
You put it on almost every time you want to do your favorite cold water activity. Your wetsuit is vital to keeping you out in the action. But do you know how it keeps you warm? There is actually a lot more going on than you think, so let’s break it down.
First Things First. What Are Wetsuits Made out Of?
Neoprene. It’s is a type of petroleum-based rubber that is filled with millions of balloon-like cells. Those cells are filled with air which acts as insulation to hold heat in. It was developed by Dupont in the ’30s and has been evolving ever since.
The neoprene keeps you warm by trapping a thin layer of water next to your body. That water is quickly heated by your body temperature and trapped against your skin by the tightness of the wetsuit. Once the water is heated by your body it makes you feel warm.
Does neoprene keep you warm in these conditions?
The tighter the wetsuit is, the thinner the layer of water will be, which will keep you warmer. That is why you want a wetsuit to fit you as snug as possible. To be the warmest you can be you’d have no water next on your skin because water sucks heat from your body. But the fact is, if you are fully submerged in water it is going to seep in. So the goal is to get a tight-fitting wetsuit that allows for as little water as possible to hit your body.
It’s Not Just Neoprene, Right?
Right. Neoprene is the main component of your wetsuit and can be thought of like the core of your suit. Other materials are put directly onto the neoprene to make it more comfortable for the person wearing it and to make it more waterproof.
In most cases, wetsuits will have 3 main layers. The layer closest to your skin can also be referred to as an inner lining. It is often made of fleece, polyester, nylon, kevlar, or other materials that feel good on your skin.
The layer on the outside that touches the water can also consist of a variety of fabrics or rubbers. It is very common for companies to use a very non-porous type of rubber layer that is totally impermeable. And finally, the middle layer is our pal Neoprene.
So What Are the Numbers About?
This middle neoprene layer is what is used to determine the sizing on wetsuits which is measured in millimeter. If you look at wetsuits you will notice that the sizing is indicated by numbers and slashes (ex. 4/3mm or 5/4/3mm).
The first number is the thickness of the neoprene in the part of the wetsuit that covers the core of your body like your chest, stomach, and pelvic region. Those are the most important areas to keep warm when it comes to stopping hypothermia which is why the neoprene is thicker in that area.
A general rule of thumb about neoprene is that the thicker it is, the less flexible it is. However, today’s neoprene is super stretchy, even when the neoprene is thick. Wetsuits can be designed to have very thick amounts in the core area because there is hardly any movement or flexibility that needs to happen in that immediate area.
Deeper Into the Numbers
If your wetsuit contains 2 numbers like a 3/2mm, that means the thickness of the neoprene around your chest is 3 millimeters and the thickness of the neoprene on the legs and arms is 2 millimeters. If your suit has 3 numbers that simply indicates a difference in thickness between the legs and arms.
I live in San Francisco where the ocean water runs 55 to 60 degrees. I also hate being cold so I use a Rip Curl 5/4/3 that keeps me plenty warm. That means my core thickness is 5 millimeters which is very thick. The thickness of the legs of the suit is 4mm which is also very thick. I bodyboard so my legs don’t do a ton of knee bending so it works for me.
The thickness of the arms is 3 millimeters which I do sometimes feel is a bit thick and may impede my paddling a bit but I prefer the trade-off of being toasty or even hot in the water. It is important to note that some wetsuits only have one number and that simply means the thickness of the wetsuit is the same throughout the arms and the core areas.
How Accurate Are the Numbers?
It is generally thought that most companies measure only the inner neoprene layer when adding sizes to their suits. Keep in mind though, there are stories out there about the thickness of wetsuits being calculated with the added space of the outer and inner linings. That would mean on a 3/2, the thickness of the neoprene may only be 2.5mm and the other .05mm is covered by the inner lining and outer layers.
How Thick Do You Need Your Wetsuit to Be?
It all depends on the water temperature and how your body handles the cold. If you are in water that is pretty warm around 65 to 75 degrees a 2/1 suit will likely keep you plenty warm. If you are going to be in water that runs 60 to 68 degrees then a 2/1 could still work but I would recommend a 3/2 for this water temp.
When you get into colder water from 57 to 63 degrees a 4/3 should do the trick for most people. If you don’t like being cold like me look into a 5/3. For water from 50 to 57 a 5/3 or a 5/4 will probably be okay but for anything colder it would probably be smart to go with something in the 6 range depending on the flexibility needed for the activity you are doing with the suit on. Check out this water temp chart for more info!
So to answer the question of, ‘Is neoprene warm?’, Yes, neoprene can keep you as warm as you want. Just make sure your wetsuit fits snug and is flexible and thick enough for what you want to do and you should be good to go.
