[wathdoc]

Although mainly a problem in head out immersions there is a tendency to pool blood centrally(chest especially),with associated increased cardiac output,and peeing. The problems occur when rescued,the bllod volume has been reduced but supported by the increased density(the water). So when you get out,there is a loss in hydrostatic support,the Arterial blood pressure can drop,with unconsiousness and Cardiac arrest. Thats why I understand that when people are rescued from lengthy immersions,they are got out horizontally. As I said this is especially true in head out immersions,but when you get out,either get lifted out horizontally,or very very slowly vertically. I suspect the main problem you will get if fit,is dizzyness.It may be worth while having some salt replenishment in drinks,as you would when dehydrated. Get checked out by your GP,look for postural hypotension. Its all guesswork,but take care,and good luck.