Exceeded NDL by a bit, but computer cleared me. What should I do?

[Jcp2]

We rarely used tag lines for people or gear unless we had a disabled or elderly diver onboard.
Nor did we have the time or patience to let people float around willy nilly.
If you are diving so close to edge that 15 minutes of leisure actually precludes DCS, you are way too close to the edge.
If not, we didn't have time nor patience for cockamamie schemes to increase one diver's personal comfort level.
Then again we rarely did less than three dives a day unless they were mix dives.

You do understand that despite our objections, a significant number of active divers would qualify as “elderly” to the layperson.

 

[100days-a-year]

I identify as elderly when a discount is involved but get around pretty good for a curmudgeonly old codger.

 

[The Chairman]

In boat diving there is truly little chance of avoiding exercise.

So adjust your diving accordingly. Too many people "ride" their NDLs to get their money's worth. Back off a bit. Shave off some bottom time. add a minute or more to your safety stop. You can't control the weather, but you can control yourself!

Quite often we hear the term "undeserved hit". There is no such thing as no one deserves DCS. There are misunderstood hits, and more often than not, it comes down to people not making accommodations for things like rough or cold seas, fast currents, and feeling a bit puny. NDLs, even on your PDC are for ideal conditions and need to be modified as conditions become less than ideal.

 

[BlueTrin]

If you display SurfGF like @scubadada says you’ll see that you can noticeably lower your GF by just doing a very slow ascent after your safety stop like @The Chairman said.

You could easily drop 10% on the SurfGF by doing 1m/min ascent from your safety stop meaning that even if you were diving 80% GFHi, you’d surface with 70% by using a slow ascent (or less if you do accelerated decompression, depending of the profile)

I was looking at a recent dive profile and when the computer cleared me for the surface, SurfGF was obviously 80% but the GF at my depth of 3m was about 36% so in these 3m the GF will go from 36% to 80% if I ascend immediately, you can lower this a lot just by slowing down and stop 1 minute at each meter of ascent. (In this case I elected to stay 3 minutes longer after clearing the obligation and that lowered my GF to 68%, from 80%)

 

[scubadada]

...Quite often we hear the term "undeserved hit".

Unexplained.

 

[100days-a-year]

Unexplained.

Unexpected. Because no one expects the Spanish Decompression Sickness

 

[The Chairman]

Unexplained.

Unexpected. Because no one expects the Spanish Decompression Sickness

These are the same thing as misunderstood as far as I'm concerned. Don't let minor semantics blind us to the ramifications of calling any hit "undeserved". That implies that they did everything right and still got hit when in fact, there were factors that caused their DCS, whether they understood the vectors or not. You can either throw up your hands and abandon all hope, or you can look a bit closer at ancillary factors that might contribute to the problem.

However, and back to the main subject, NDLs, including those algorithms used by our PDCs, usually account for the lowest common denominator. Exceeding them by as much as 20% will probably not result in DCS for the average person on an average dive. However, you can follow your PDC perfectly, but given a particular diver not allowing for various conditions, come away with DCS.

 

[scubadada]

Hi @The Chairman

There's no misunderstanding. The three of us understand this phenomenon and have our preferred descriptors.