extend safety stop or exit water???

[partridge]

I am at the end of the dive and have a lot of psi left.

Which is better for extending bottom time on my next dive?
extending the safety stop or exiting the water?

Thanks

 

[abowie]

I am at the end of the dive and have a lot of psi left.

Which is better for extending bottom time on my next dive?
extending the safety stop or exiting the water?

Thanks

If you're breathing air it makes no difference.

If you're breathing O2 and you can't breathe it on the surface, it might make some difference.

Get hold of a copy of V Planner and have a play...

 

[raskas]

what kind of dive is it ?
if you are within 3 pressure groups of an NDL, or the dive was deeper than 30m then all you need to do is the recommended 3min stop at 5 meters, then get out of the water, you'll off gas more if your SI is longer, rather than at 5 meters doing an extended safety stop
Of course if you are doing deco diving its a different story

 

[partridge]

I only dive air. Down here in the bottom of the Philippines, we do not have nitrox yet or any other mix.

Typically my dives are to 80 to 120 feet and usually push the limit there. The reason I ask is there is not much to see at 15 feet at the exit point so it would be a sacrifice to extend the safety stop....but if the sacrifice were worth it.....

Oh I use a Suunto Stinger so will my question have different answers if using different models?

 

[Jai Bar]

If you are breathing air during the dive, then off-gassing is better in the surface. That is because the difference between ambient pressure and the partial-pressure of absorbed nitrogen in tissues is higher (compared to a staying in a long stop at 3-5 meters).
So, as long as you are diving within NDL times and you are allowed to surface, get out of the water, rest, drink and wait for next dive.

However, if there are too many things to see at 15' and you've got plenty of air, why rush out of the water? Enjoy the dive. Assuming you are diving with a computer, it will not impact too much the surface interval for the next dive. After all, the interesting side of the world is underwater, ain't it?
Moreover, an extended safety stop is recommended in cases where you "push the limits" too much. So, if you are making 2-3 dives a day, all of them to 20-30 meters, better not to rely on the computer and have an extended stop at 3-5 meters (and also extend the surface interval). That will reduce your chances to get acquainted with a recompression chamber...

 

[MikeFerrara]

When planning a dive with tables they won't give surface credit until you surface. At "safety stop depth" they allow you to not add that time to bottom time but still there isn't any SI credit. When using a computer, I guess it depends on which computer.

In reality though, a good ascent strategy can prevent the formation and growth of bubbles which can indeed leave you in better shape for the next dive.

 

[RPanick]

Current recommendations are to make a 1-2 minute stop at half your depth, so if you are at 80 feet, stop at 40 for a couple of minutes, and then do a stop at 15 feet.

Of course there are variations to this, which if you search around you can likely find. I don't think any of the computers incorporate this into the recommendations yet, at least for NDL.

It probably won't help your off gas times, but it might help you keep from getting bent.

 

[partridge]

Thanks for the input guys.

I do rely heavily on the computer for my ascents as I take my sweet time going up. I also try to spend as much time as I can underwater. On a single 80 tank I can get up to 75 mins. I usually bleed the tank down to 200 psi. I know this is not recommended but you have to see the dive site and conditions to understand this. The last 15 mins is spent at 20 feet and below. Sometimes I just get bored at this depth at the surface area because theres nothing there.

This weekend I will try to surface a distance away so I can enjoy an extended safety stop. This means a surface swim to get out of the water....but lifes full of compromises.

 

[Warren_L]

Thanks for the input guys.

I do rely heavily on the computer for my ascents as I take my sweet time going up. I also try to spend as much time as I can underwater. On a single 80 tank I can get up to 75 mins. I usually bleed the tank down to 200 psi. I know this is not recommended but you have to see the dive site and conditions to understand this. The last 15 mins is spent at 20 feet and below. Sometimes I just get bored at this depth at the surface area because theres nothing there.

This weekend I will try to surface a distance away so I can enjoy an extended safety stop. This means a surface swim to get out of the water....but lifes full of compromises.

The amount of time you can breathe off your 80 depends on how deep you go. I can get close to an hour and a half with a shallow dive aroudn 25 ft, but go down deep, it drops off quite dramatically.

 

[jplacson]

Paul, yes different computers give different bottom times. Suunto is known to be one of the more conservative brands out there. I've heard Oceanics give you about 8 min more bottom time before hitting deco.

I use a Vytec, and I appreciate the safety margin of Suuntos. If I push the limits, I'd better be trained for it... thus end up using gauge mode anyway. If you're not trained for more aggressive diving, I don't see the sanity in 'pushing the limits' if you don't know what to do if you should accidentally exceed those limits. As much fun as I have diving, I'd rather cut a dive short and live to dive another day!

Extend your SIT and your Suunto will be happy... and don't violate the ascent rate either (just a note, Suunto's FASTEST ascent rate is slower than Uwatec's slowest ascent rate)