what do you do if?

[Sideband]

However this is how it's been taught to me: the idea is, that if you enter a "rapid ascent", which could mean either that you somehow miss your stops or you just ascent faster than the reccomended max speed (15m/s up to the first stop, 6m/s between stops and between last stop and surface), then you've violated the "model" behind the tables -- and to get back in to the model, you need "emergency recompression" within a short amount of time (the tables say 3 min...) Since we do not commonly dive with a recompression chamber on the RIB, going back down is the best option for increasing the preasure exerted on you -- of course, in the case where you do not detect an onset of DCS.

I can see the reasoning behind it after your explanation. Another question though. Is that 15 meters/second and 6 meters/second? That's an ascent rate of 45 feet and 18 feet per second. I was taught 1 foot every 2 seconds. As you burst forth from the water do you just land on the boat and bypass the ladder?

You write one thing, which disturbs me a little:

"If my thinking is right, and you didn't have a deco obligation before the ascent, you would not have one after the ascent."

What I meant was that if you had remained within NDL up to the point of the ascent, then going shallower would not put you over those limits unless you spent a rather lengthy time at the shallower depth (due to the longer MDT at shallower depths). Of course on every dive you on-gas and off-gas and hopefully do so in a controlled manner. I was not trying to suggest that you didn't. I was saying that the over agressive ascent could be made up for at 15 feet in a nice safety stop.

Thanks for the explanation. I understand it now. Not sure if I agree with all of it but then I don't know if I agree 100% with the tables I learned on either.

Joe

 

[voop]

I can see the reasoning behind it after your explanation. Another question though. Is that 15 meters/second and 6 meters/second? That's an ascent rate of 45 feet and 18 feet per second. I was taught 1 foot every 2 seconds. As you burst forth from the water do you just land on the boat and bypass the ladder?

My bad! It should be 15 meter/minute and 6 meters/minute. I will go back and edit the original post since it is a crucial difference....

(although I like the throught of bypassing the boat ladder....)

What I meant was that if you had remained within NDL up to the point of the ascent, then going shallower would not put you over those limits unless you spent a rather lengthy time at the shallower depth (due to the longer MDT at shallower depths). Of course on every dive you on-gas and off-gas and hopefully do so in a controlled manner. I was not trying to suggest that you didn't. I was saying that the over agressive ascent could be made up for at 15 feet in a nice safety stop.

I see what you mean, and it may be as you describe. I honestly do not know enough to figure out if a rapid ascent can be made up for at 15m, or that there may be other things in play. The procedure described above was what we were taught, but I believe that the precondition was that most dives would be deco-dives -- which might shift things quite a bit.

We could try to ask in the DrDeco forum if the good doctor can help us out here?

Thanks for the explanation. I understand it now. Not sure if I agree with all of it but then I don't know if I agree 100% with the tables I learned on either.

Joe

Glad to be of help. I do not know if I agree 100% either, but I do know that I do not know enough to disagree......if you see what I mean

Cheers,

 

[Sideband]

We could try to ask in the DrDeco forum if the good doctor can help us out here?



Glad to be of help. I do not know if I agree 100% either, but I do know that I do not know enough to disagree......if you see what I mean

Cheers,

A good idea and I know exactly what you mean.

Joe

 

[cdennyb]

You did fine, and without trying to "micro-manage" the situation, you did what a trained professional would've done. Don't let this incident cloud your judgment as to "who" to dive with. **** happens and this was an opportunity for you to use the clear thinking and quick reflexes you have developed with "your training". Situation is done, no-one got injured and you're smarter for it, carry on to the next dive.

I would be honored to dive with you. You are the perfect dive buddy.
db

 

[GrierHPharmD]

I'll chime in with Walter that you were doing your job as a good, well-trained buddy. There comes a time when you have to make the call between helping the other person and endangering yourself, and it looks like you made it correctly.

As to his behavior afterward, who knows? Embarrassment, arrogance, poor manners, post-traumatic stress and any number of other things could be to blame.

Let me know if you ever need a dive buddy in South Florida. I'll be glad to dive with you.

-Grier