The Complete Drysuit Weight Configuration Guide: From Surface to Safety Stop

Not sure which setup is right for you?

Getting drysuit weighting wrong makes buoyancy control impossible. Too much weight and you fight inflation/deflation constantly. Too little and you can't descend.

UK drysuits typically need 10-15kg of lead. But your exact requirement depends on body composition, undergarment thickness, drysuit material, and tank type.

Here's how to get it right.

Starting Point Calculation

Begin with your 7mm wetsuit weight plus 4-6kg for typical undergarment.

If you don't know your wetsuit weight, estimate: Most UK divers need 8-12kg in 7mm wetsuit. Add 4-6kg for drysuit undergarment gives 12-18kg starting estimate.

This is rough. You must do proper weight check to refine.

Crushed neoprene drysuits: Less buoyant than membrane suits. Need 1-2kg less weight than membrane.

Membrane suits with thick undergarments: Most buoyant. Need maximum weight in the range.

Proper Weight Check Procedure

At surface in full dive kit: Empty BCD completely. Add minimal air to drysuit (just enough to eliminate squeeze, no more). Hold normal breath and float vertically. You should float at eye level with water at eye level.

Exhale fully: You should sink slowly.

If you float higher than eyes with normal breath: Add 1kg, retest. If you sink below eyes with normal breath: Remove 1kg, retest.

CRITICAL: Test at END of dive when tank is near-empty. Full 12L steel tank has approximately 2kg positive buoyancy that disappears as you use air.

If you're correctly weighted at end of dive (nearly empty tank), you'll be slightly heavy at start of dive (full tank). This is manageable, add a bit more drysuit air initially.

If you're correctly weighted at start of dive, you'll be dangerously buoyant at end. This causes runaway ascents.

Weight Distribution

Where you place weight affects trim and control dramatically.

Integrated BCD pockets (4-8kg): Central placement, easy ditching, reduces belt weight. Good starting point for most divers.

Weightbelt (remaining weight): Position LOW on hips, not around natural waist. Low positioning helps keep feet down, counteracts drysuit foot buoyancy.

Ankle weights (1-2kg per ankle): Highly effective for preventing feet-first inversion. Many UK divers find this solves their biggest drysuit problem.

Tank positioning: High on back creates head-heavy trim (good if you're naturally feet-heavy). Low on back creates feet-heavy trim (good if you're naturally head-heavy).

Recommended distribution for 12kg total: 6kg BCD integrated, 4kg belt low on hips, 2kg ankle weights (1kg per ankle).

Trial different configurations in pool before committing to open water.

Seasonal Variation

Undergarment thickness changes weight needs dramatically.

Thin summer undersuit (200-300g fleece or thin thermal): 8-12kg total typical.

Medium undersuit (400-500g): 10-14kg total.

Thick winter undersuit (600-800g Thinsulate or equivalent): 12-16kg total.

The difference between summer and winter can be 4-6kg. Always do full weight check when changing undergarments.

Many UK divers own multiple undersuits and mark their logbook: "Summer config: 10kg (6 integrated, 4 belt), Winter config: 14kg (8 integrated, 6 belt)."

This saves time on future dives.

Steel vs Aluminum Tanks

Steel 12L: Approximately 2-3kg negatively buoyant when full, neutral when empty.

Aluminum 12L: Approximately 1kg positively buoyant when full, 2-3kg positive when empty.

If you switch from steel to aluminum, add 2-3kg weight to compensate.

If your club/operator provides tanks, ask what type. Your weight configuration differs substantially.

Troubleshooting Weight Problems

Feet float up constantly: You're carrying too much weight. Excess weight requires excess drysuit air to compensate. Air migrates to feet. Reduce total weight by 2kg and add 1-2kg ankle weights.

Squeeze remains despite adding air: You're underweighted. At depth, suit compresses. You add air to eliminate squeeze. But suit re-compresses because you don't have enough weight to keep it compressed. Add 1-2kg.

Can't descend: Underweighted. Add 2kg and retest.

Rapid buoyant ascents: Too much air in suit. This suggests either overweighting (requiring excess air) or poor venting discipline. Check weight first.

Breathless feeling: Drysuit squeeze compressing chest. Add more air until breathing is comfortable. If this makes you too buoyant, you're underweighted.

Advanced Considerations

Body composition: Muscular divers need less weight (muscle is denser than fat). Higher body fat percentage needs more weight.

Gender differences: Women typically have higher body fat percentage, need slightly more weight than equivalent-height men.

Age: Older divers often need slightly more weight due to body composition changes.

Wetsuit underneath drysuit: Some divers wear thin wetsuit under drysuit for extra warmth. Adds 2-4kg buoyancy, requires equivalent extra weight.

These are averages. Individual variation is enormous. The only way to know YOUR weight requirement is proper weight check.

Record Keeping

Logbook your configurations: "12kg total: 6kg integrated BCD, 4kg belt, 2kg ankle. 400g undersuit. Steel 12L. Perfect neutral."

Next time you dive identical setup, you know exactly what weight to use. Saves 20 minutes of pool testing.

If you change any variable (undersuit, drysuit, tank type, BCD), note it and expect to adjust weight.

The Reality

Getting drysuit weight configuration right is iterative. Your first attempt will be close but not perfect. Expect 2-3 pool sessions refining before you nail it.

Once dialed in, your buoyancy control improves dramatically. You're using minimum air in suit, inversions stop, ascents are controlled.

But every time you change undergarment thickness or switch drysuits, you start the process again. This is normal and expected.

The effort is worth it. Perfect weighting makes UK drysuit diving enjoyable instead of a constant fight.

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