Wetsuit (neoprene exposure suit)

A wetsuit is a tight-fitting garment made of synthetic rubber. It works by trapping a thin layer of water against your skin.

How it works

The suit traps water inside. Your body heat warms this water so that you stay comfortable during the dive. This process relies on the neoprene material to act as an insulator. While the rubber itself provides some protection, the warmed water layer does the heavy lifting.

Thickness matters for your comfort. In Koh Tao, a 3 mm suit usually suffices for most year-round dives. However, I used a 5 mm suit during my 2018 trip to Komodo because the currents were cold. If you dive in the Tubbataha Reef in 2024, you might need a 5 mm suit even when the surface feels warm.

Temperature drops quickly at depth.

Safety and planning

Thermal regulation affects your dive time. Cold water makes you breathe faster and increases your gas consumption rate. I once stayed down for only 35 minutes in 12°C water because my core temperature dropped too fast. This happens because shivering uses up oxygen that you need for your computer.

Planning depends on the local climate. You must check the average water temperature before you pack your gear. A thin suit is fine for Cebu in May, but it fails in the deeper, colder thermoclines of the North Sulawesi region.

Check your local forecast.

Common buying mistakes

Many divers buy suits that are too large. If the neoprene gaps at your waist or wrists, heat escapes quickly. A loose suit allows water to flush through the body constantly. This constant movement prevents the thin layer of water from warming up.

Used gear requires careful inspection. Always check the seals for cracks before you buy used gear. I found a 3 mm suit in Anilao that looked perfect until I saw the micro-cracks near the zipper. These small holes let cold water in and ruin the insulation properties.

A tight fit is vital for warmth.

Wetsuits relate directly to buoyancy control. Neoprene contains tiny nitrogen bubbles that compress as you descend. At 10 m, your suit will feel much tighter than it did at the surface. You might need to add more weight to your belt to compensate for this loss of buoyancy.

This compression also affects thermal protection. Because the material compresses under pressure, the insulating properties decrease as you go deeper. If you dive to 30 m, your 5 mm suit effectively becomes much thinner. You should account for this temperature change when planning long, deep dives.

Test your buoyancy in the shallows.

Wetsuit (neoprene exposure suit)