I just bought a new set of Al63s for my wife for Christmas. She has a SAC of .35 so there is plenty of bottom time for her above 150 which is about her "feeling good" max of diving anyway. Any longer and she gets cold or maybe just bored. I always wonder why anyone would carry so much more air unless they are underground.
Doubles recommendations for a small framed women?
- Thread starter kathydee
- Start date
Please register or login
Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.
Benefits of registering include
- Ability to post and comment on topics and discussions.
- A Free photo gallery to share your dive photos with the world.
- You can make this box go away
StreetDoctor
Contributor
There's a lot of reasons to carry doubles bigger than AL63's, I'm sure you could do a search and find out all about it.
ScubaInChicago
Contributor
halocline
Contributor
If she enjoys diving with these tanks there's absolutely no reason to use bigger ones unless you're planning a dive in which you need more gas. Personally, I like AL63s MUCH better than AL80s and would gladly trade my AL80 for a 63 of the same year/condition.
There's a lot of hype about using bigger tanks, when actually it's more fun IMO (in and out of the water) to use smaller tanks. It's about matching the dive to the tanks.
For a long, shallow dive, smaller tanks might be ideal.
For diving in technical depths, 63s don't give you enough gas to do the dive and maintain safe reserves.
For diving in technical depths, 63s don't give you enough gas to do the dive and maintain safe reserves.
BobbyT22
Contributor
This is a DIR forum, and I am not DIR, so I respectfully defer to those that are. I am sure there are good, valid, reasons why double 63's are not the best choice for DIR diving.
But they sure are fun! I enjoy mine, and if anyone wants more info please let me know. I'll be happy to discuss in another forum.
Rob
But they sure are fun! I enjoy mine, and if anyone wants more info please let me know. I'll be happy to discuss in another forum.
Rob
No, there is no reason not to use 63s for DIR diving! But they're good for longer, shallow dives, not for deep ones. The reason is actually pretty simple, and it's called "rock bottom", or "minimum gas". We always carry enough gas to get ourselves and a teammate up from the deepest point of the dive to the first gas switch (which may be the surface on a deep, non-decompression dive), making all appropriate stops. That amount of gas reserve starts to get substantial as you go deeper -- for example, it's 40 cu ft from 100 fsw. Since your gas consumption continues to increase as you go deeper, there comes a point where small tanks just don't give you much bottom time AND enough gas reserve. I'm fairly sure Kathy is interested in doubles for deep dives in Monterey, and 63s would quickly be inadequate for that.
But I would imagine that sets of small doubles would be great fun for shallower dives. Doubles just dive so much nicer than single tanks!
But I would imagine that sets of small doubles would be great fun for shallower dives. Doubles just dive so much nicer than single tanks!
elan
Contributor
If I'm not mistaken AL63 quite short. That can create problems with trimming them.
BobbyT22
Contributor
Yes, they are short, 24 inches. But mine trim very well for me. I am 5-9, about 170. Probably closer to 175 due to all the holiday festivities 
. I had my baby doubles out yesterday in a local quarry by the way, probably my last dive for 2009, and they trim and balance much much nicer than a single.
TS&M, thanks for the explanation on rock bottom.
Merry Christmas to all.
Rob
. I had my baby doubles out yesterday in a local quarry by the way, probably my last dive for 2009, and they trim and balance much much nicer than a single. TS&M, thanks for the explanation on rock bottom.
Merry Christmas to all.
Rob
OP
I'm looking for a longer range first, and perhaps deeper later if/when I progress through training. I don't want to limit possibilities.
I checked with my fundies instructor who suggested sticking to LP 85's and/or HP 100's for tank volume & future dive potential.
Will start sampling soon
Thanks again for the advice.
Similar threads
