Surfing and diving
Water pulls heat away about twenty times faster than air of the same temperature, which is why you get cold in the water even in summer and the session ends when the warmth runs out while the waves are still there. You wear Glovii heated vests under a wetsuit or a drysuit: the neoprene softshell takes direct contact with water, the heating covers the front and the back, and the working depth reaches one hundred metres. The 32 W output is about three times higher than in Glovii heated clothing for land, because under water you need far more of it.
The single-battery version with an 11.1 V battery heats for about 115 minutes, has the switch directly on the battery and works on the board, in the kayak, on the sailboat, on the jet ski and for kitesurfing and wingfoiling. The diving version has two batteries for about six hours of work in total and a wrist remote that confirms every level change with a vibration, so you switch between three heat levels in murky water without looking at any indicator. Once you are out of the water, warm up with the power bank heated poncho and the beanie with the hidden switch before you take off the wet suit.