The first time you dive a drysuit, it feels like learning buoyancy all over again. You're managing an air space around your whole body, not just your BCD. Air moves to the highest point, whether that's your shoulders or your feet. And you'll almost certainly need more weight than you used with a wetsuit. None of it is hard once it clicks, but it's a real skill.
Why drysuit diving feels different
A drysuit contains a layer of air around you, trapped in your undergarments. As you descend, water pressure compresses that air. The suit squeezes against you, and you lose both buoyancy and insulation. As you ascend, the air expands, and you gain buoyancy. That's the same physics as your BCD, except the air space is distributed around your body and moves when you change orientation.
Managing squeeze on descent
"Squeeze" is the suit pressing tighter as you descend. It can pinch skin in folds of the suit and, more importantly, flattens your undergarments so they insulate less.
- Add small bursts of air to the suit through the chest inflator as you descend, enough to relieve squeeze and keep undergarments lofted. Don't add enough to get buoyant.
- Descend under control. A slow, feet-down descent gives you time to equalize ears and the suit.
- Mask squeeze still applies. Exhale through your nose as usual.
Venting air: the shoulder dump valve
Most drysuits have an automatic exhaust valve on the upper left arm or shoulder. It releases air when it's the highest point on your body and the valve is open.
- To vent, raise your left shoulder or elbow slightly so it's the highest point, and air escapes.
- The valve's dial adjusts how easily it releases air. Many instructors teach new drysuit divers to keep it fully open during the dive, and to adjust with experience.
- Venting on ascent is continuous. As you ascend, air expands. Keep venting through the ascent and safety stop to avoid a runaway ascent.
Suit or BCD for buoyancy?
Here's where agencies and instructors differ:
- Suit for squeeze, BCD for buoyancy. Many teach adding only enough air to the suit to stay comfortable and warm, and controlling buoyancy with the BCD.
- Suit for both. Others teach using the suit for buoyancy in some situations.
What almost everyone agrees on: managing two air spaces at once is harder than managing one. Follow your instructor's approach, and keep the suit's air to the minimum you need for comfort and warmth when you're starting out.
Weighting: you'll need more
Drysuits and undergarments are buoyant, so most divers need more weight than with a wetsuit. How much more depends on your suit material, undergarment thickness, tank, and body. There's no reliable universal number, so do a proper weight check.
- Do a weight check at the surface. With a nearly empty tank's worth of buoyancy in mind, vent the suit fully (squat or hug your knees in the water to push air out) and empty the BCD.
- Aim to float at eye level while holding a normal breath. Exhale, and you should begin to sink slowly.
- Adjust in small increments. Add or remove small weights until you hit that point.
- Re-check at the safety stop at the end of a dive. With a lighter tank, you should still be able to hold a safety stop comfortably.
- Distribute weight thoughtfully. Some divers move weight toward the upper body, such as trim pockets or a weighted backplate, to help keep their feet down.
Feet-up: the classic drysuit problem
If air migrates to your legs and feet, your feet float up and you can end up inverted. Air trapped in your feet can't be vented through the shoulder valve, and in the worst case it can drive an uncontrolled, feet-first ascent. Prevention is the main defense:
- Don't carry too much air in the suit. Less air means less to migrate.
- Stay horizontal or slightly head-up. Avoid pointing your feet toward the surface.
- Consider ankle weights or heavier fins if you're consistently floaty-footed. Some divers use a suit with a better leg fit or gaiters to reduce the air space in the legs.
- Practice recovery with an instructor. The recovery technique, which usually involves tucking and rolling to get your head up, needs supervised practice.
Other skills to practice
- Stuck inflator. Disconnecting the suit's low-pressure inflator hose while venting is a key emergency skill.
- Removing and replacing the weight system with drysuit gloves or thicker hand protection.
- Donning and doffing, including zipper closure checks. A partly open zipper floods the suit.
- Burping the suit before the dive to remove excess air.
First-dive setup checklist
| Check | Why |
|---|---|
| Zipper fully closed | An open zipper floods the suit |
| Inflator hose connected and tested | You need it to manage squeeze |
| Dump valve setting as instructed | Controls how easily air vents |
| Undergarments suited to water temperature | Warmth comes from undergarments |
| Weight checked and logged | More weight than a wetsuit is normal |
| Seals comfortable, not too tight | Tight neck seals can restrict blood flow |
Still choosing a suit? See our best drysuits and drysuit undergarments guides.
Your first dives: a sensible progression
- Start in a pool or confined water to practice venting, weighting, and recovery skills.
- Move to shallow, calm open water with good visibility.
- Keep dives simple so your attention stays on buoyancy.
- Build up to your usual depths and conditions over several dives.
Gear that helps new drysuit divers
Diving Ankle Weights
$Best for: Drysuit divers who struggle with floaty feet
Small ankle weights help keep your feet down while you learn to manage air in the suit. Many divers eventually stop needing them as their trim and technique improve.
Why it makes the list
- Helps prevent feet-up positions
- Inexpensive
- Easy to add or remove
Watch out for
- Adds effort to finning
- Not a substitute for good air management
Affiliate disclosure: We may earn a commission from qualifying purchases made through links on this page, at no extra cost to you.
Drysuit Zipper Wax or Lubricant
$Best for: Anyone who owns a drysuit
Waterproof zippers need regular care. Use the product your suit's manufacturer recommends for its zipper type; metal and plastic zippers can need different care.
Why it makes the list
- Extends zipper life
- Makes closure easier
- Cheap compared with a zipper replacement
Watch out for
- Use the correct product for your zipper type
- Don't over-apply
Frequently asked questions
How much more weight do I need with a drysuit?
It varies by suit material, undergarments, tank, and body. Most divers need more than with a wetsuit. Do a surface weight check with the suit fully vented rather than relying on a formula.
How do you vent a drysuit?
Most drysuits have a shoulder or upper-arm exhaust valve. Raise that shoulder so it's the highest point and air escapes. Keep venting during ascents.
Should I use my drysuit or BCD for buoyancy?
Approaches differ between agencies. Many teach using the suit only to relieve squeeze and the BCD for buoyancy. Follow your instructor's training.
What is drysuit squeeze?
The suit compressing against your body as you descend. Adding small amounts of air to the suit relieves it and keeps undergarments insulating.
How do I avoid going feet-up in a drysuit?
Keep minimal air in the suit, stay horizontal or slightly head-up, and consider ankle weights or heavier fins if needed. Practice recovery with an instructor.