Is this a safe practice?

[mksmith713]

I'll be diving in the Keys next month and I'll have 2 buddies with me.
They both dive frequently and have decent air cumsumption rates.
I, on the other hand, dive whenever I get a chance but nowhere near as much as they do.
I was wondering if it's OK to dive as a trio and for me to start my ascent early (when I get short on air) and let them continue the dive?

 

[Don Wray]

No. Most of the problems with newer divers occur enroute to or on the surface. The proper way for trio dives is the plan is formulated on the diver with the most air consumption rules the day. When they run low on air, the dive is over for all 3.

 

[TSandM]

This is one of those risk analysis things, and it's going to depend to some degree on the dive site and conditions. Is it a shallow dive off an anchored boat, where your buddies will accompany you to the upline, and someone on the boat will be there to assist, should you have any issues on the surface? Is it a dive in limited viz, where no one will be able to see you while you are ascending? Are you diving in an area where there are currents, and you might end up somewhere you don't want to be? Is there fishing line or boat traffic there?

Transitioning from diver at depth to diver out of the water is one of the times of instability and change, and higher risk for discovering equipment problems (say stuck dump valve, or a BC that won't hold air at the surface). Reverse blocks and alternobaric vertigo occur on ascent, too. Surface conditions can change and become problematic while a dive is going on. In general, I'd say descent and ascent are the times when you MOST want to be with your buddies, because you may need assistance. Especially if you have less experience than your buddies, I would discourage you from ascending alone, except in the most benign circumstances.

If you need more gas than they do, rent bigger tanks

 

[tstormdiver]

Why not try to find a larger volume tank, so you can stay down longer? If you guys dive as a group, then you all should end the dive together when the first reaches the planned air consumption. It's not a "written in stone" rule that this MUST be done, but what if you have a life threatening issue on your solo ascent? who will help you. Plus if you are in an area with boat traffic, more people can= more visibility. What if an unexpected current catches you & not them,.. or them & not you.... you get the point. Just my $.02

 

[Arizona]

No. Most of the problems with newer divers occur enroute to or on the surface. The proper way for trio dives is the plan is formulated on the diver with the most air consumption rules the day. When they run low on air, the dive is over for all 3.

Sound advice Don. You could also choose shallower dives to extend your dives. Discuss it with the DM or dive group leader as he/she may have good suggestions as well.

Safe diving,

Arizona

 

[mksmith713]

If I could find a shop that rents 100's or 120's and they dive 80's, that would probably work out OK.
Question is......who rents anything other than 80's?

It sucks being an air hog........

 

[jridg]

Many shops will have 95's, 100's or even 120's to rent. You may have to ask around. I know local shops here do rent 100s.

 

[tep]

Check around. While it seems most shops are focused on the Al80 for rentals, I think that at least half the shops in my area offer larger tanks, for a larger price.

Or, if one of your lower-consumption buddies has a larger tank, then borrow the larger tank from them and have them use the AL80 that you rent. Maybe you'll get similar bottom times from that exhange.

 

[krawdady]

Check with Conch Republic Divers. I'm pretty sure they rent steel 100"s. That may even things out and allow you all to stay even.

 

[Charlie99]

Most reefs in the keys are shallow. One plan could be for the three of you to loop past the boat and drop you off. The key thing is that your buddies should keep an eye on you until you ascend the boat ladder.

If they can't maintain positive visual contact all the way until you start climbing the ladder, then you should all surface together.

I have used this plan many times in SE Florida drift dives. Part of my briefing is to tell my buddy that he can command me to stick with him for any reason or no reason at all. The agreed upon signal for "stick with me for the ascent" is the buddy signal (banging the side of index fingers together) followed by "thumbs up".

As others have noted, the ascent is one of the critical phases of the dive and you should not do it unobserved.

Charlie