Water conducts heat away from your body 25 times faster than air. Without thermal protection, even tropical water at 80°F will chill you on a long dive. A wetsuit traps a thin layer of water against your skin, which your body heats — the neoprene insulation then prevents that warm water from being flushed away. The thickness you need depends entirely on water temperature.
Wetsuit Thickness Guide
| Water Temp | Thickness | Typical Use |
|---|---|---|
| 80°F+ (27°C+) | Rash guard or 1–2mm | Tropical reefs, Caribbean |
| 72–80°F (22–27°C) | 3mm full suit | Warm-water diving, summer temperate |
| 60–72°F (16–22°C) | 5mm full suit | Spring/fall temperate, deeper tropical thermoclines |
| 50–60°F (10–16°C) | 7mm full suit + hood | Cold-water recreational |
| Below 50°F (10°C) | Drysuit | Ice diving, year-round cold water |
Top Wetsuits
Cressi Morea 3mm
An affordable, comfortable 3mm suit for tropical and warm-temperate diving. The high-stretch neoprene moves well underwater, and the back zipper makes solo donning easy. Reinforced knee panels add durability where you need it most. A solid first wetsuit for new divers.
Scubapro Everflex 5/4mm
Scubapro's premium 5mm suit uses X-Foam neoprene for superior stretch and warmth retention. The 4mm arms and legs reduce bulk where you need mobility most, while the 5mm torso keeps your core warm. Front zipper eliminates the cold flush down the spine that back-zip suits allow. One of the most comfortable cold-water wetsuits on the market.
Mares Reef 3mm
A versatile, budget-friendly 3mm suit with strategically placed stretch panels for comfortable movement. The flat-stitch seams reduce chafing on long dives. An excellent entry-level choice for divers starting in warm water who want quality without overspending.
Fit Is Everything
A wetsuit should fit snugly everywhere — no gaps under the arms, behind the knees, or along the lower back. Air pockets in the suit create channels for cold water to flush through, eliminating the insulation benefit. A suit that's too tight restricts movement and breathing.
Try suits on dry, in the shop. Pull the suit fully up to your crotch before zipping — most fit problems come from the suit not being pulled up far enough. Squat, reach overhead, and simulate a swimming motion. If the suit restricts any of these, try the next size or a different brand. Every manufacturer cuts differently.