Drysuit Undergarments This is our Drysuit undergarment section. Undergarments are made of many different materials. The most common are polartec, thinsulate and merino. Everyone has pluses and minuses it really comes down to what you prefer. Johns Quick Tip’s: Maintenance of Undergarment. This is one of those things that divers just take for granted. They wash their undergarments like there clothes and then wonder why they do not feel as warm as they used to. The reason behind this is surfactants. Surfactants are what clean fabrics. The problem is that if there is any residue left behind your undergarment will not wick moisture like it used to and you will then be colder. There are solutions to this; 1. Instead of washing your undergarment every time try soaking it in water and hanging it out in a shaded area to dry. 2. If your undergarment does need a cleaning there are special cleaners that are made for high performance fabric. McNett Corporation has a great product called Revivex Synthetic Fabric Cleaner. This product will clean your undergarment without harming the wicking ability of your undergarment.