Gear & Skills
What to Wear Scuba Diving
From a rash guard in the tropics to a drysuit in the cold, here's how to pick exposure protection that keeps you warm and comfortable.
What you wear scuba diving depends almost entirely on water temperature. In warm tropical water (28°C+) a rash guard or thin shorty is plenty. As it cools you move up through 3mm, 5mm and 7mm wetsuits, adding a hood, gloves and boots. In genuinely cold water, a drysuit keeps you dry and warm. When in doubt, dress a little warmer: you lose heat far faster underwater than in air.
- 28°C+ / 82°F+
- Rash guard or 2mm shorty
- 24–28°C
- 3mm full wetsuit
- 18–24°C
- 5mm + hood
- Below 18°C
- 7mm or drysuit
Water pulls heat from your body around 25 times faster than air, so even 'warm' water will chill you over a long dive. Exposure protection keeps you comfortable, and a comfortable diver is a safe, relaxed diver. Here is how to choose.
Wetsuit thickness by water temperature
| Water temperature | What to wear |
|---|---|
| 28°C+ / 82°F+ | Rash guard, dive skin or 0.5–2mm shorty |
| 24–28°C / 75–82°F | 3mm full wetsuit |
| 18–24°C / 64–75°F | 5mm full wetsuit, plus hood and boots |
| 14–18°C / 57–64°F | 7mm wetsuit or semi-dry, with hood, gloves, boots |
| Below 14°C / 57°F | Drysuit (with appropriate training) |
These are starting points, not rules. How cold you feel depends on your body, dive length, depth and how many dives you do in a day. If you run cold or plan long, repetitive dives, size up a level.
How a wetsuit actually works
A wetsuit traps a thin layer of water against your skin, which your body warms and which then insulates you. That is why fit is everything: a loose suit lets cold water flush through and steals your heat, while a properly snug suit keeps that warm layer in place. It should be close-fitting without restricting your breathing or movement.
Wetsuit vs semi-dry vs drysuit
- Wetsuit — neoprene that traps a warmed layer of water. Simple, affordable, ideal from tropical to cool water.
- Semi-dry — a thick wetsuit with better seals at the wrists, ankles and neck to limit flushing. A good step for cooler water.
- Drysuit — keeps water out entirely, insulating with the undergarments you wear beneath. Essential for cold water, and it requires its own short course because it changes how you control buoyancy.
Don't forget the extremities
You lose a lot of heat from your head, hands and feet. As water cools, add a hood (a surprising amount of warmth for little bulk), boots (which also protect your feet and pair with open-heel fins), and gloves. Even in warm water, a thin layer can protect against stings, scrapes and sun on the surface.
Warmer suits are more buoyant, so the more neoprene you wear, the more weight you'll need to descend comfortably. See our guide to how much weight you need and check your buoyancy whenever you change exposure protection.
Get the gear right, every dive
Diving Standard helps you log conditions, plan for water temperature and dial in your buoyancy. Free, and built by divers.
Get the Diving Standard appFrequently asked questions
What wetsuit thickness do I need for scuba diving?
It depends on water temperature: a rash guard or thin shorty above 28°C, a 3mm full suit from 24 to 28°C, a 5mm with a hood from 18 to 24°C, and a 7mm or drysuit below 18°C. When unsure, choose the warmer option.
Do I need a wetsuit to scuba dive in warm water?
Not strictly, but most divers wear at least a thin suit or rash guard even in warm tropical water. It slows heat loss over a long dive and protects against stings, scrapes and sun. Water cools you far faster than air.
What's the difference between a wetsuit and a drysuit?
A wetsuit traps a thin layer of water that your body warms, while a drysuit keeps water out entirely and insulates with the clothing worn underneath. Drysuits are for cold water and need a short course because they change how you control buoyancy.