Trimming Yourself Out
Greg Galford Jan 25, 2025
Let’s enter the exciting world of TRIM! Yea, yea, I know, not what most people think about during diving, but mastering trim in the water has a bunch of benefits.
- Reduced air consumption (not having to swim yourself upright every time you stop swimming reduces workload)
- Good trim is critical for photography
- Overall comfort in the water reduces workload and increases perception of the world around you
- Allows you to descend or ascend in a level position
Commonly trim in scuba is a diver’s ability to remain in a horizontal position while in the water once you stop moving (with neither forward motion or hands or feet moving). In some environments, trim is critical. Wrecks, caverns, swim throughs, silty bottoms, etc are places where trim will be a skill that needs to be used.
How do we achieve trim?
- Start by checking yourself in the water (I assume that your weighting is close to where it needs to be at this point – more on weighting in another blog) – while neutrally buoyant, stop swimming, put your hands and feet into a natural “holding” position. Most people prefer to have there knees bent and feet elevated and their hands out in front and below them. This is also the position you will see experienced divers using during dives.
- Once you are in the position that feels comfortable for you, don’t scull or kick and see what happens. Most people will sink by the feet. Some will sink head first. If you can maintain the horizontal position without either, congrats – skip the rest of this :-)
- If like most people you sink feet first, then you need to adjust the center of gravity more toward your head. First, move your tank up a bit (just so that when you put your head back it touches the regulator) and second, you can move some weight from the lower weight pockets into higher trim pockets. One thing you want to watch when moving weight to trim pockets is the weight there in not ditchable, so make sure you can swim up against the weight you keep there.
- Some people will sink head first (not very common), If this is the case, reverse what we did above, move the tank down slightly (while kicking your legs should not hit the tank). Move weight down from trim pouches to weight pockets at the wasit. If you are still having trouble (this happens with thicker wetsuits sometimes), you can use ankle weights. Ankle weights generally range from one to three pounds per ankle and are easy to use.
When setting up your trim, do so a little at a time. Don’t radically change your weight location and tank position at the same time. Start with one on one dive and another on the next if you need more. Also, as you change exposure systems, tank type and BCD, things will shift, so be ready to keep adjusting as necessary.
Also, if you are struggling to get trim, this is taught as part of the Peak Performance Buoyancy class. A class I always suggest for photographers and those that just want to become more comfortable divin for the reasons I mention above.
