So yesterday I had my first adventurous dive session. I went with my friend the instructor to a spot we both know well, and one of his favourite spearfising locations. I am still in my Orca swimming suit, but it was a hot day and I survived quite well. I think one of the reasons for this is that I am moving a lot more than he does. My technique is improving, but I am doing a lot more splashing around, adjusting my mask, and generally spluttering than he is, so I am generating heat at the expense of saving oxygen, the better I get, the colder I will be. I borrowed a speargun and failed dismally at getting anything, partly because of the low visibility but mainly my own inadequacy.
I learned about dehydration the hard way. It was a hot day, we were captivated by the undersea world and before I knew it I had been diving away in the salty environment for a couple of hours, and hadn’t had a drink for 3. So I ended up headachy and struggled to drag all my kit back up the hill.
Dehydration is a problem for freedivers because of the number of descents they are likely to make in a day. As I undersatnd it every time your body gets under pressure the fluids are pushed from your extremities to your core, you kidneys think ‘hello! too much liquid, let’s have a wee’ and so the excess gets sent to your bladder, when you surface and the liquid floods back to your extremities again you are a bit more dehydrated. Over a period of time you will lose more liquid than if you were bobbing around the surface, and the deeper your dives the more you will lose.