When sailing, temperature fluctuations can be intense: day or night, windy conditions, coming from the side or going backward and more, while getting wet, and sometimes freezing wet or burning up. So with that, thermal base layers come in handy to maintain body temperature.
Having thermal base layers means staying warm. Many sailors enjoy long sailing outings in early winter in all wind conditions, when it’s cold out but the boat is not moving very much, and with plenty of opportunities to pass by other sailors and even someone walking along the waterfront. One reason thermal base layers are so important is that, after the boat stops moving and is just sitting there, the muscles in your legs start to tighten up and you start sweating more and it can start to feel a bit chilly. When you’re sweating more and changing the thermostat on the heating of your boots, and then wearing those same thermals that you sweat in, it’s not really appropriate for you to be wearing waterproof and windproof sailing boots and socks to prevent cold drafts. So wearing a thermal base layer keeps you warm and the rest of your body dry.
However, you can only keep yourself warm for a certain amount of time, and then if you’re doing the other things that a sailing sailor does, such as taking off your shoes, it can make them wet and that can be even worse. That’s why you need to have the insulation in the base layer as well, so that it can protect you for the rest of the time.
How do I get the right base layer?
As far as fabrics go, it can be split up between cold weather and warm weather materials. What we see most often is leather linings, which in sailing sometimes could be only a mix between nylon or neoprene, or even cotton. But there’s one material that’s very warm, that works with all climates – merino wool. There are two fabrics that look similar to leather, but in sailing they are not the right choice – they could be too thick. Then you have synthetic fabrics with wool linings. That could work well for the warm conditions of the summer or spring, but when the spring comes around in autumn and winter, these synthetic fabrics could get really wet and then warm up and then get too hot, and if you’re roasting or burning you could end up burning the wool as well.
In general, we see that synthetic fabrics are better for warm weather sailing, which is probably why most sailors out there prefer a synthetic base layer to a wool base layer, at least if they’re going to be out for a long time and doing lots of activities. So there’s a lot of mixed fabrics, with nylon, neoprene and merino wool. If you’re sailing in spring in a warm climate and you want to warm up quickly, then nylon is the best for that. If you’re sailing in winter and don’t want to get wet, then nylon might be the best option, although merino wool is pretty good at keeping you warm, especially when there’s only really one layer of insulation.