Safe Accent Rate !!!

[Chad_Ordelheide]

I'm curious how many people accend at the suggested rate. It seams that as I go up and down over reefs, my computer often beeps at me telling me I'm going up too fast.Usually, on my final accent I'm fine. Anyway, if anyone has any thoughts to add please do!! Happy Diving!!

 

[Uncle Pug]

My ascent rate changes... and gets slower the shallower I am. Much slower than the 30fpm suggested.

 

[D_O_H]

My ascent rate changes... and gets slower the shallower I am. Much slower than the 30fpm suggested.

I have been making a conscious effort on my last 5 dives or so to make an entire dive without irritating my computer. I have yet to be successful. I have no problem keeping it under 60fpm, but have not been able to keep an entire dive under 30.

 

[Uncle Pug]

The last 10' should take a minute.

 

[DennisS]

Interesting way of looking at ascent rates. Correct and Incorrect Ascent rates are based on whether the computer beeps.

 

[Mark Vlahos]

I try to keep it at or below 30 fpm. I do occasionally go too fast like 45 fpm for a few feet, but those alarms seem to be rare and only for a lift of less than 5 feet or so.

I am not perfect (my wife will certainly attest to that) but I am trying (my wife will attest to that too).

It seems that when I go out on a dive boat without a buddy and am teamed with the buddy du jour, he always wonders why it takes me sooooo long to get up to the safety stop, and from there to the surface. This even happens after we have talked about it before getting wet. Come to think of it, they also wonder why I get out of the water after a safety stop with more air in my tank than they have when they thumb the dive at 60 feet. Remember the Captain said back on the boat with 700 PSI, not thumb the dive with 500.

Mark Vlahos

 

[Chad_Ordelheide]

Interesting way of looking at ascent rates. Correct and Incorrect Ascent rates are based on whether the computer beeps.

Sounds like you don't like the idea of trusting the computer!? How do you judge you accent rate DennisS? I have a bar graph on my computer. It's the traditional Green, Yellow and Red, the red is accompanied by a beep. Seams like an easy way to monitor it to me!

 

[Ber Rabbit]

A depth gauge and a stopwatch work just as well for judging the ascent rate. A 30 fpm ascent means you go up 1 foot every 2 seconds. I try to teach my students to count the seconds to themselves in the pool and maintain 30 fpm or slower, we don't have the luxury of training with computers and the college students usually can't afford to buy one of their own.

My computer beeps when you ascend too quickly but it doesn't have a graph telling you how fast you are going. I dove with an Uwatec once that beeped every time I moved my arm to look at it, that was really annoying.
Ber :lilbunny:

 

[DennisW]

My computer never beeps (doesn't have a beeper). However, when I am going over reefs and / or other obstacles, it will sometimes move into the yellow or red area for ascent rate. I only pay close attention to it during my ascent to the surface, however if I am moving up the side of a large reef or wreck, I do watch my ascent rate.

 

[Rick Murchison]

Y'all need to heed what Uncle Pug's saying... from a bubble growth perspective, an ascent rate of 30 feet per minute at the surface is the same as 120 feet per minute at 100' - or, put another way, if you feel that 30 feet per minute is "correct" at a depth of 60 feet, you should realize that to achieve the same rate of bubble growth potential near the surface you should limit your ascent rate to about 10 feet per minute (see Pug's recommendation above).
Not so easy. Takes practice and discipline.
That said, there are other factors to take into account for efficient offgassing and further modifications to the ascent profile are warranted to accomodate them... but a general rule of "shallower=slower" is a good one.
Rick