 UPTDs
Fo simplicity's sake, BSAC's take is you have a max of 300 for any un-broken period of diving.
A period of diving is only broken when you have a 24hr "gap"
Therefore if you were to accumulate 100 UPTDs on each of 3 consecutive days, you'd need to have day #4 as a "break"
However if you look at the RepEx Table, you'll see that there's alot of safety margin built-in
My understanding, is that BSAC did it this way so you wouldn't have to know/remember how many consecutive days diving meant what exposure was allowed (i.e. carry a copy of the RepEx table around with you)
Don't forget, that in addition:
1. You're racking up lots of N2 so your no-stop times are going to diminish as you go through the week
2. Your body core temp drops with each dive (UK especially) and that typically by the end of a weeks diving your body core will have dropped by 1-2C and you need to get the heat back into the core - you're getting hypothermic (dangerous in itself) and cold increases the risk of DCI
Therefore in addition to the UPTDs, there are lots of other good reasons to take a break  |