Interesting to read some of the comments and questions above. There seems to be a difference in approach to diving here and in what some of you are doing. On the charter dives, we don't plan maximum depth and dive time. The skipper finds a lump of reef and drops the anchor. There is a dive brief where the terrain including the range of depths is described. It is not a guided tour or instruction. We dive with a buddy and go where we choose. The general direction of the dive may be discussed with your buddy but it is pretty much jump in and see what takes your fancy. We regularly monitor the remaining air and time to no decompression limits. The ascent to the surface begins when either divers air gets low or the NDL is approached. It really is that simple. That is the way every diver and charter boat I've been on over here works. I don't see any problem with this mode of diving nor any need to complicate it further by being prescriptive about maximum depths, profiles and dive times. This is recreational diving down to about 30 m.
To get to the surface with 50 bar in your tank, you begin your ascent with say 60 to 80 bar depending on depth. That gives time for a safety stop. If you are diving right up to the NDL, then as a safety precaution, I can see the merit in having extra air up your sleeve to allow for decompression stops that may be flagged by your computer. From what I can gather on this thread and from footnotes on the dive charts, this would typically equate to about an extra 5 to 10 minutes. Starting to sound like the ten minute rule.
NW grateful diver, I read a couple of your articles. Thanks. I see the merit of at least getting some idea of what to do if you exceed no decompression limits. It doesn't sound that complicated.
I'm planning a dive trip overseas soon where we're likely to be diving to the 30 m limit more regularly so this discussion has been useful. Outside the course, I've not yet met anyone who uses the ten minute rule, so insisting that it is observed creates obvious problems with your buddy and the Dive Master. I don't mind digging in my heals on this one but only if it is warranted. It appears it isn't and I'd maybe cut the rule back to 5 minutes depending on depths being dived and the amount of air remaining. I'm planning to do a nitrox and deep diving specialty course to give a better understanding of the risks factors involved. The book mentioned above may also be useful.
I'm still interested to hear from anyone who can describe what the Suunto computers use to trigger the NDL. Clearly it was not triggered by some cells exceeding saturation limits.
I'd also like to hear if anyone knows if the 10 minute rule is promoted by SSI.
Thanks for your input to date.
To get to the surface with 50 bar in your tank, you begin your ascent with say 60 to 80 bar depending on depth. That gives time for a safety stop. If you are diving right up to the NDL, then as a safety precaution, I can see the merit in having extra air up your sleeve to allow for decompression stops that may be flagged by your computer. From what I can gather on this thread and from footnotes on the dive charts, this would typically equate to about an extra 5 to 10 minutes. Starting to sound like the ten minute rule.
NW grateful diver, I read a couple of your articles. Thanks. I see the merit of at least getting some idea of what to do if you exceed no decompression limits. It doesn't sound that complicated.
I'm planning a dive trip overseas soon where we're likely to be diving to the 30 m limit more regularly so this discussion has been useful. Outside the course, I've not yet met anyone who uses the ten minute rule, so insisting that it is observed creates obvious problems with your buddy and the Dive Master. I don't mind digging in my heals on this one but only if it is warranted. It appears it isn't and I'd maybe cut the rule back to 5 minutes depending on depths being dived and the amount of air remaining. I'm planning to do a nitrox and deep diving specialty course to give a better understanding of the risks factors involved. The book mentioned above may also be useful.
I'm still interested to hear from anyone who can describe what the Suunto computers use to trigger the NDL. Clearly it was not triggered by some cells exceeding saturation limits.
I'd also like to hear if anyone knows if the 10 minute rule is promoted by SSI.
Thanks for your input to date.
