I live in a land-locked state, so most of my diving is week-long or weekend trips to the Carribean.
When I first started diving, my mentor was the LDSO, who told me that a good dive profile for a week of diving is: Deepest dives at the beginning of the week (for instance, 100 feet on Monday), followed by successively shallower dives on subsequent days (80 feet on Tuesday), with the last days' diving being quite shallow and short (30 feet on Friday). This makes sense to me, as a way to take the highest nitrogen loading early, and spend the rest of the week taking on smaller amounts. By the off-gas day (Saturday), your body shouldn't have to do much work to off-gas to acceptable levels before flying home (Sunday).
I've overheard the new LDSO, on several occasions, telling customers and students something different when we prepare for trips. If there is a planned dive on our trip that is deeper than the customer has been before, he suggests doing not-so-deep dives first, to "build up to it". For instance, if a 100-foot dive is planned, he recommeds an 80-foot dive on Monday, followed by a 90-foot dive on Tuesday, and slowly approaching 100-feet by the end of the week.
I understand the new LDSO's point from a narcosis standpoint. My opinion is that deep dives should become deeper over multiple trips - for instance 80 feet at the beginning of this trip, so that divers have time to adjust to narcosis and understand it's effect on them. Next trip, try an 85-foot. Next trip, maybe 90. All after taking a deep-diving class, of course :05:
But I think the idea of "building up to" deep dives in one trip is counter-productive to a good week-long dive profile from the standpoint of DCS. If you do deeper dives over the course of a week, I think your nitrogen loading on the last day is going to be quite high and your body may not be able to off-gas as much before flying home.
Is either of these two theories correct? Or does it matter at all which way you go, from a DCS standpoint?
When I first started diving, my mentor was the LDSO, who told me that a good dive profile for a week of diving is: Deepest dives at the beginning of the week (for instance, 100 feet on Monday), followed by successively shallower dives on subsequent days (80 feet on Tuesday), with the last days' diving being quite shallow and short (30 feet on Friday). This makes sense to me, as a way to take the highest nitrogen loading early, and spend the rest of the week taking on smaller amounts. By the off-gas day (Saturday), your body shouldn't have to do much work to off-gas to acceptable levels before flying home (Sunday).
I've overheard the new LDSO, on several occasions, telling customers and students something different when we prepare for trips. If there is a planned dive on our trip that is deeper than the customer has been before, he suggests doing not-so-deep dives first, to "build up to it". For instance, if a 100-foot dive is planned, he recommeds an 80-foot dive on Monday, followed by a 90-foot dive on Tuesday, and slowly approaching 100-feet by the end of the week.
I understand the new LDSO's point from a narcosis standpoint. My opinion is that deep dives should become deeper over multiple trips - for instance 80 feet at the beginning of this trip, so that divers have time to adjust to narcosis and understand it's effect on them. Next trip, try an 85-foot. Next trip, maybe 90. All after taking a deep-diving class, of course :05:
But I think the idea of "building up to" deep dives in one trip is counter-productive to a good week-long dive profile from the standpoint of DCS. If you do deeper dives over the course of a week, I think your nitrogen loading on the last day is going to be quite high and your body may not be able to off-gas as much before flying home.
Is either of these two theories correct? Or does it matter at all which way you go, from a DCS standpoint?