A 5/4 thermal steamer wetsuit is a high-performance wetsuit designed for use in colder water temperatures. The thickness of the neoprene provides excellent insulation and warmth, while additional materials such as wool helps to further trap and retain body heat. These wetsuits are ideal for surfers and water enthusiasts looking to stay warm and comfortable in chilly water conditions.

It's important to understand what the term "5/4" means when it comes to thermal wetsuits, also known as steamers. A 5/4 steamer refers to the thickness of the neoprene used to make the suit. The first number (5) represents the thickness in millimetres of the neoprene in the torso and upper body area, while the second number (4) represents the thickness in millimetres in the arms and legs. The thicker the neoprene, the warmer the wetsuit, which is important for surfing in colder water temperatures. Therefore, a 5/4 wetsuit has 5mm thick neoprene in the torso and upper body area, and 4mm thick neoprene in the arms and legs, this thickness provides insulation and warmth, making it a good option for surfing in colder waters in New Zealand. The term "steamer" refers to the fact that this wetsuit style covers the surfer's entire body, like a "steam engine". Thermal wetsuits are designed to keep the wearer warm and comfortable for longer periods of time, allowing for more time in the water.