And then someone reaches for weights…..
Descending is not as easy as it initially sounds. Anyone can hang enough lead around them to get beneath the water; the skill is getting under with the correct weight so you’re safe when at depth.
Avoid going for the weight first. There are a few questions to consider. Have you actually done a weight check? If so, and you think you’re correctly weighted, then it’s a case of calming your breathing, settling, and then ensuring as you descend that you empty your lungs fully. Most people think they’re exhaling but there’s still a bit there to get out!
If you’re drysuit diving then the whole “extra air” thing will start at the surface. Have you expelled as much excess air from your suit as you can before getting into the water?
When descending, and therefore expelling the air from your BC, are you actually getting the air out? I’ve had many situations where someone says “I can’t get down” and I come along and there’s still a lot of air in the BC. Be patient and make sure your arm is as high as possible.
Are you vertical? You want as little surface area as possible to help you on your way. As a side effect, this can help your ears during the descent too.
You shouldn’t be sinking fast when you descend. If you are then you’re undoubtedly overweighted. It might be considering if your expectations are where they need to be in terms of your rate of descent.
Keep a note of your weight and what you were wearing for that dive. By keeping a good log then you can build up your knowledge of what weight you need to dive with. Is your breathing heavier because you had a long walk to enter the water? Or perhaps it’s cold, so not only are you wearing more thermals/thicker wetsuit, but your breathing is heavier as you hit the cold water on entry.
It may be that you need a bit more weight but avoid doing that as a go-to solution. Work on some other aspects first. If you’re 4kg over (and I’ve worked with divers and taken over 10kg off them before) then consider what impact that has at 30m. Taking a bit of time to work on your weight, alongside trim, will lead to safer and more enjoyable dives.