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I am too vertical and lose trim

Buoyancy4 causes1 mission
1

What is happening

Your torso is higher than your fins, so each kick pushes water down instead of letting you glide forward. You may stir up silt, tire quickly, or feel yourself rolling to one side.

Quick self-check
2

Why it happens

Ordered from the most common cause down. Open one to see the mechanism behind it.

When the centre of gravity is ahead of the centre of buoyancy, your body pitches head-up and feet-down. Moving some weight rearward can change this balance.

  • weights only in front pockets
  • no trim pockets
  • uneven left-to-right distribution
Scuba Diving — Here’s How to Improve Your Trim

Excess lead requires more gas in the BCD. That gas lifts your upper body and makes diagonal swimming more demanding.

  • too much lead
  • a lot of gas in the BCD
  • an upright profile with more drag
Dive Training — Air Consumption Essentials

A new exposure suit changes buoyancy and the distribution of volume around your body. Your previous lead and trim may not give the same position.

  • a different wetsuit thickness
  • a new suit
  • no weight and trim check
Scuba Diving — Here’s How to Improve Your Trim

Gas in a drysuit can move to your feet and make stabilising difficult, including turning you upside down. A poorly fitting drysuit has separate risks that are not fixed by adding lead.

  • gas in the feet
  • a drysuit that is too large
  • no drysuit training
DAN — Five Lessons for Cold-Water Diving
3

What to try on your next dive

One thing, not ten. Give it a full dive before you judge it.

Your next dive · one task

Horizontal trim check

Trimmoderateone calm section at neutral buoyancy
  1. With your buddy, choose a clear area and establish neutral buoyancy.
  2. Swim slowly with your head, torso, legs and fins in one line.
  3. Ask your buddy to watch for pitch and any rolling.
  4. Note what in your configuration is tipping you before making a change.
You have done it whenYou stay within 30 degrees of horizontal and within 1.5 m of the target depth.
If that goes well
  • Keep equipment close to your body.
  • Ask an instructor or experienced buddy whether a small change in weight distribution is appropriate.
4

How you will know it is working

Deviation from horizontal · degreesKeep your body close to horizontal at a stable depth.
Published referenceValueSource
GUE recreational pass criterionno more than 30 degrees from horizontal and within 1.5 m of target depthGUE Fundamentals Standards v9.1

Your buddy observes your profile as you swim slowly at a stable depth. Record whether your head, torso, legs and fins stay in one line.

Safety
  • Do not correct a badly fitting drysuit with extra lead or ankle weights.
  • Drysuit diving requires suitable equipment and training; you must be able to vent trapped gas.
  • Do not sacrifice buoyancy control to look horizontal.
Please read. Dive Confidence is free reference material published by ProDive Shop. It supports training, it does not replace it. Nothing here overrides the standards of your certifying agency, the instructions of your instructor or divemaster, or the limits of your certification. It is not medical advice — ear, sinus, cardiac, respiratory and anxiety problems should be discussed with a physician trained in diving medicine. Every technique described should first be practised under supervision in conditions appropriate to your training. Sources are cited on every page so you can read the original guidance yourself.