Aluminum 80s versus larger steel tanks

[gopbroek]

Well…. this thread has taken its SB wander off topic but I am really interested in the AL80 verse S120’s debate. Christi / Dave what type S120 tanks are being used and what is the buoyancy of the S120’s verse AL80’s?
I am assuming Dave and Jeremy run the PST 3500 PSI tanks with an E-1.3 / F -10.3 lb. buoyancy spec as opposed to the generic AL80 with an E +4.4 / F -1.4 lb. buoyancy. The AL80 config normally puts me at an hour plus on Lion Fish hunts with excursions to 110+ and average depths to around 50’, bunny runs to Columbia shallows will give me 90+ minutes with 1000 PSI in the bottle.
I am a relatively new diver (2.5 years / 250 dives) and I am a fat medium height guy (50+) who is not in good shape. I have always dived AL80’s (other than a couple herd dives with 65’s in Maui) and only recently invested in a download cable for my computer so I could track my ‘SAC’ rate. For warm Caribbean water my present configuration runs @ 9 LBs weight with an AL80 and my SAC is .39 to .44 depending on the activity. As I understand it with a S120, I would need to drop 5 lbs. weight to maintain buoyancy with a minimum bottle (which I like to do) but it would put me very heavy on the initial point in the dive and due to the heavy bottle my CG would shift high to my back, which explains Christi’s roll statement.
Currently I am very happy with Tres Pelicanos and Servando or Jorge as DM and Servando is the Lion Fish killer / spotter ‘extraordinaire’. One of these days I need to book a trip with Dave or Jeremy to check out the 120’s but as it stands I am happy with the AL80 and often run against DECO with the AL80 (EANx) bottle and I am not sure what I would do with the additional gas on a 120.

 

[chillyinCanada]

Christi, thanks for going to the trouble of posting those profiles but somehow I doubt that square profiles are getting those times. Ergo, I'm assuming they were multi-level dives (just as I did in the first place). Therefore, I ask, what are the profiles of these multi-level dives? What times at what depths? How long at total depth, at 50; at 30; at 20; 10? Is a 90 minute dive spent noodling around at 15'?

 

[ReefHound]

I am happy with the AL80 and often run against DECO with the AL80 (EANx) bottle and I am not sure what I would do with the additional gas on a 120.

Thats a good point that I meant to make earlier. On deeper dives I'm running into NDL limitations so the bigger tank would only be of much benefit if it was filled with nitrox. Put Another Twenty Dollars In.

 

[Christi]

Christi, thanks for going to the trouble of posting those profiles but somehow I doubt that square profiles are getting those times. Ergo, I'm assuming they were multi-level dives (just as I did in the first place). Therefore, I ask, what are the profiles of these multi-level dives? What times at what depths? How long at total depth, at 50; at 30; at 20; 10? Is a 90 minute dive spent noodling around at 15'?

You're welcome and Yep, I actually said they were multi level profiles in my post - as 95% of the dives here are and all of those listed are ML So the profiles would be similar on any tank with just about any DM here so that's really not relevant to this discussion.

As I said, they are standard/general samplings provided as a courtesy and they are COMPUTER dives, so I'm not going to take the time to break down depths and times - I don't use the wheel to plan dives anymore. I'm not getting into nit picking. "Dont got no time fo dat." Hahahaha

 

[Mike]

So all the people who don't like steel tanks are all wrong? Am I getting this right?

Well, first off who doesn't like them?

Here is a $10 bill or a $100 bill, which one do you want? Here is a small margarita, or here is a large one, which one do you want? Here is less air on your dive or more air on your dive which one do you want? I mean we have to go through this all again?

I mean, I ask you theoretically, if in Cozumel you could wave a big magic wand and suddenly every single dive operation had steel high pressure tanks and Al 80s in their inventory and every diver now was given the option of do you want an Al 80 or at no additional cost a steel tank with 50% more air, do you really think the majority of divers would stick with Al 80s? If not, why?

 

[chillyinCanada]

Christi, you offered. And if the intention of my original question wasn't clear to you, sorry about that. My response post was a bit more detailed as to what I meant by what kind of " profiles are you people diving" to get 90 minute dives. Apparently, it was necessary to spell it out. Your efforts were wasted, perhaps even deliberately obtuse.

Perhaps I'd best ask for average depth, though now I'm asking others.

 

[Mossman]

Well, first off who doesn't like them?

Here is a $10 bill or a $100 bill, which one do you want? Here is a small margarita, or here is a large one, which one do you want? Here is less air on your dive or more air on your dive which one do you want? I mean we have to go through this all again?

I mean, I ask you theoretically, if in Cozumel you could wave a big magic wand and suddenly every single dive operation had steel high pressure tanks and Al 80s in their inventory and every diver now was given the option of do you want an Al 80 or at no additional cost a steel tank with 50% more air, do you really think the majority of divers would stick with Al 80s? If not, why?

And bigger dive boats are better than smaller ones?

 

[cvchief]

Well, first off who doesn't like them?

Well, I don't know what their deal is. Perhaps they are off their meds, but I have heard people say they don't like using the big steel tanks with the weighting.

Here is a small margarita, or here is a large one, which one do you want?

Well that is an unreasonable. Ill have the large and please start making the next one.

HOWEVER, I would prefer the smaller Margarita Alison at Kinta to the larger margarita at Parrilla Mission.

And bigger dive boats are better than smaller ones?

Well, not all of them. Just the ones that are bigger and FASTER. Unless you like getting two SS checks while on the ride down and back from Senior Club. (snicker)

 

[Skittl1321]

Here is a small margarita, or here is a large one, which one do you want?

Well, I want the small margarita. Preferably with a half shot instead of a full one if it wasn't pre mixed...

I've never used a steel tank, so I have no idea if I prefer it. But you can't assume that just because you prefer something everyone else does.

Not to mention this "no extra cost steel tank" doesn't exist. The ops that use them DO cost more than most that don't.

 

[cvchief]

Well, I want the small margarita. Preferably with a half shot instead of a full one if it wasn't pre mixed....

Ok. You lost me right there. That is wrong on so many levels.....