In polar regions, where the ocean water can be as cold as -1˚C/30˚F, a drysuit is the only thing that will keep you dry during a dive. The type of dry suit you use is not important so long as it fits you correctly and you are proficient in using it.  Insulating undergarments will trap air against your body to keep you warm. The colder the water, the more (or thicker) layers of undergarments you will need. We recommend wearing two or three layers, depending on your drysuit. The first layer should be a type of material that helps wick any moisture away from the body, while the second and third layers should be should thicker insulating material, such as fleece, synthetic pile or thinsulate. The one-piece jumpsuit style is the most common and comfortable configuration of dive wear and is available in a variety of thickness depending on your drysuit and the water temperature. The right accessories will also help you have a more comfortable experience. We recommend a 5-10mm neoprene hood with face and neck seal, regular 5-7mm neoprene semi-dry gloves or mitts, and three-finger mitts over five-finger gloves. Finally, it is important to bring a warm hat and gloves to wear before and after each dive, and a wind and waterproof spray jacket to keep the cold wind off your drysuit.