Trim and The Mystical Art Of Buoyancy Control Part III
When your instructor or dive guide suggests that you are not in trim, don’t slap them silly and call them out over body shaming! All they are suggesting is that some of your floaty bits and some of your sinky bits could be slightly better adjusted! This is what they meant by “Keeping in Trim!”
By now you have your weights correctly adjusted and you can operate your BCD without replicating a polaris missile but your legs keep sinking and you end up rolling onto your back like a stranded turtle. This is where trim comes in. It’s all about weights again. But this time it is the where that is important.
A couple of physiological facts.
Men have heavy legs. Older women have legs that float. This will obviously affect the angle in which you attain when you are neutrally buoyant. You want your body to be as horizontal as possible so here are some tricks to help.
If you are finding that your legs are always sinking, put one of your weights onto the tank band. A weight will hold fine if you thread it onto the band after you have secured your BCD. The Velcro on the band will hold everything firmly. If you are investing in a BCD, then look for one with trim pockets. These are normally mounted on the back about level with the tank band. Another solution is to have the BCD mounted slightly lower down the tank, but this does result in a few collisions between your head and the regulator.
On the other hand, if your legs are reaching for the sky, ankle weights are a solution. These can be the training weights for joggers that you can buy from sport shops. Alternatively you can buy heavy fins. The old style jet fins made from black rubber are great for this!
What about always rolling over?
Think about boats. These are stable when all of the weight is down in the bottom of the boat. Look how you have your weights distributed on your weight belt. If you have them arranged so that they are positioned either side of the buckle on your front then that is ideal. If you have an odd number, then put the single weight on your tank band. A lot of these issues can be sorted by buying good equipment. A weight integrated BCD puts the weights exactly where they should be and generally come with trim pockets too.
Final floaty bits that can upset the apple cart.
There is one more item that affects your buoyancy and that is your exposure protection. Wetsuits float, thick wetsuits float a lot and dry suits really float. All of these items are affected by pressure too. The deeper you go, the more they compress. A number of our guests comment that they find getting neutral in our wetsuits harded than when they did their open water course. That’s because we use 5mm full suits and they trained in 2.5 mm shorties. With a thick wetsuit you have to be a lot more proactive in maintaining your buoyancy. Expect to add a lot more air to your BCD when descending and remember to let this extra air out on the way back up.
Finally, don’t forget that empty tanks float too!