We often hear the terms thermal active underwear or thermal underwear. For most people, there seems to be no difference, and one might think they are the same thing. And this, my friends, is where you are mistaken! Thermal active and thermal underwear are two completely different products. So let's take a closer look at them and see what really sets them apart.

The basic and, in fact, most important difference – at least for divers – is the issue of sweat-wicking. In the case of thermal clothing, it does not wick away sweat, meaning that as you exert yourself, the clothing will become increasingly damp and start to cool your body. It also does not provide adequate ventilation. It is most often made from thick materials, such as natural wool or cotton.

Thermal active underwear provides the user with protection against wind, burning sun, or a cold, piercing gust of wind. It is a specific type of clothing that helps maintain a constant body temperature, protects against cold and hypothermia, while also providing an appropriate level of thermal insulation. At the same time, it also maintains a high level of ventilation and moisture-wicking. It does not heat our body on its own but merely maintains a constant temperature and the heat generated by the body.

In that case, is the BARE Ultrawarmth thermal underwear only for cold waters and should it only be used in the autumn-winter period? Nothing could be further from the truth!

I personally dive all year round and always in a drysuit. For my first dives with the new Bare underwear set, to test it, I went to Malta right in the middle of summer. The weather was perfect, and the July temperatures were very noticeable. The water temperature was 25°C, while the air temperature was always above 30°C. In this case, the test underwear set served as my undergarment.

At the outset, I must note that the comfort offered by Ultrawarmth exceeded my wildest expectations. But let's start from the beginning. A very important aspect when choosing thermal active underwear is getting the right size. The underwear should be snug against the body. In this particular case, fitting will not be a problem, as BARE Ultrawarmth has as many as 16 different sizes, so everyone can find something perfect for themselves. Interestingly, to better fit such a key element ensuring thermal comfort, the underwear has separate sizing for women and men, taking into account anatomical differences. When ordering, sizes can be mixed and matched to get a perfectly fitting set, e.g., size L pants and an XL top.

In Malta, I did over a dozen dives at depths ranging from 10 to 40 meters. During this time, the underwear performed exemplarily and, importantly for clothing that is very close to the body, nothing chafed or rubbed. This is because so-called flat seams were used, minimizing discomfort.

However, these are not the only details worth mentioning. The designers at BARE have used, among other things, a low pullover-style neck cut, which makes it very easy to put on, a foot loop to keep the legs in place, and my favorite feature – a thumb loop, which is very useful when getting dressed. In the women's version, a contoured waistband with an adjustable drawstring was used.

The longer you use this underwear, the more you see that it is a well-thought-out and refined product, created based on the important needs of users.

Diving in cold waters, such as the Baltic Sea, at depths below 40 meters and a water temperature of 4°C, also did not exceed the capabilities of this underwear. I performed a series of such dives with the Bare Ultrawarmth underwear as additional support under my undergarment, as a first layer, and additionally with a heating vest. The whole setup worked beautifully, ensuring a very pleasant dive.

From a diver's perspective, an undeniable advantage of the underwear is how quickly it dries in case of a leak. In fact, you just need to turn it inside out and hang it up, and after a few dozen minutes, you can use it again, enjoying 100% of the properties it offers.

In summary – the Bare Ultrawarmth underwear is so versatile that every diver, regardless of their level of advancement, the time of year, or where they dive, will be satisfied with it. Properly fitted, it can play the main role in warm waters or be an excellent supplement during long dives in low-temperature water.