Are you looking for a wetsuit,

Wetsuits are [...] simple, Neoprene suits that are typically used where the water temperature is between 10 and 25 °C (50 to 80 °F). The foamed neoprene of the suit thermally insulates the wearer. Although water can enter the suit, a tight fitting suit prevents excessive heat loss because little of the water warmed inside the suit escapes from the suit. -Wikipedia

Or a Drysuit?

Drysuits are used typically where the water temperature is between -2 and 15 °C (28 to 60 °F). Water is prevented from entering the suit by seals at the neck and wrists; also, the means of getting the suit on and off (typically a zipper) is waterproof. The suit insulates the wearer in one of two main ways: by maintaining pockets of air between the body and the cold water in standard air-containing fabric undergarments beneath the suit (in exactly the way that insulation garments work in air) or via (additional) foamed-neoprene material which contains insulative air, which may be incorporated into the outside of the drysuit itself. -Wikipedia