Under suits provide the layers of thermal protection you need to enjoy your drysuit diving. Generally they come as base layers which wick the perspiration away from your body and thermal layers that provide you with warmth. Water conducts heat away from your body up to twenty five times faster than air, so substantial thermal protection is required even in summer in UK waters, but you will find the amount required varies significantly throughout the year and with other factors such as the depth of your dive, its duration and the amount of physical activity you engage in. Therefore it is important to have a selection of thermal wear to allow for different circumstances. Neoprene drysuits require less additional insulation than membrane suits with crushed neoprene of various thicknesses somewhere between the two. At Yu Diving we offer a comprehensive range of base and thermal layers to suit all of your diving requirements.