Aluminum 100s vs HP Steel 120s

[Jaeger62]

Hi all. I am planning a dive trip to Cozumel in January and think I have it narrowed to 2 dive ops. The primary difference is AL 100s vs HP Steel 120s.

How much difference in amount of bottom time should I realistically expect between the two? It looks like the difference in cost is fairly negligible ($30ish total cost difference).

Both look to be very reputable dive ops, just trying to get a grasp of how much real difference there may be.

Thanks!

 

[shurite7]

This is a question that doesn't make a whole lot of sense. Considering all things equal, the 120 would last longer since it has 20 more cft of air. We all know not all things are equal therefore, the answer will have an infinite amount of responses, none of which will be helpful. A comparison between an AL100 vs. a ST100 would make more sense.

I don't like the AL100 because it is wider in diameter than the ST120 or an AL80. I don't like changing my straps from one to the other. Since the ST120 is the same diameter as the AL80 or my ST100s my choice would be the 120s.

Only you can make the decision. Contact the operators and ask them questions. Let that be your deciding factor.

 

[JohnN]

+1 and remember that the service pressure of that AL100 is 3300 PSI. With a 'standard' 3000 PSI AL80 fill, you only have marginally more gas than the AL80.

Plus the tank is an absolute pig ~41 lbs empty

 

[time2sail]

Note, your bottom time will most likely be limited due to the no deco tables more than the amount of air that you have unless you tend to use a lot of gas or on shallower dives.Steel 100's are nice also...

This is one of the better dive ops,Home - Liquid Blue Divers, run by a husband and wife team from my area...they relocated to Cozumel several years ago and are very knowledgeable and trust worthy dive op.

 

[Carlos Danger]

Hi all. I am planning a dive trip to Cozumel in January and think I have it narrowed to 2 dive ops. The primary difference is AL 100s vs HP Steel 120s.

How much difference in amount of bottom time should I realistically expect between the two? It looks like the difference in cost is fairly negligible ($30ish total cost difference).

Both look to be very reputable dive ops, just trying to get a grasp of how much real difference there may be.

Thanks!

Definitely much prefer the Steel HP 120s.

This is not so much for reasons of bottom time, but rather for their near ideal buoyancy profile for single tank recreational diving. This combined with the extra capacity makes them hard to beat in terms performance, which ultimately should contribute to extended dive times. On the downside they may take a few dives to get acclimated to and get your weighting right, especially if all you have previously used are standard AL 80s.

My personal all-time record in Coz using a Steel HP 120 is 128 minutes on EAN 36, but typical bottom times are generally between 80-95 minutes depending on conditions and dive profile, etc.

Hope this helps!

 

[rhwestfall]

service pressure of that AL100 is 3300 PSI. With a 'standard' 3000 PSI AL80 fill, you only have marginally more gas than the AL80.

AL80 @ 3000 = 77.4
AL100 @ 3000 = 90.9

14+/- cu-ft - some may feel that is more than "marginal".... hmmmm that is the size of the AL13 some even use as a pony.....

Now, as said above, that AL100 is just a pig with it's weight, is a PITA with it's larger diameter, and is annoying on the buoyancy characteristics....

I have one, and rarely ever use it....... one of the worst purchases I have made....

YMMV

 

[Jaeger62]

This is one of the better dive ops,Home - Liquid Blue Divers, run by a husband and wife team from my area...they relocated to Cozumel several years ago and are very knowledgeable and trust worthy dive op.

That is actually one of two shops I am deciding between.... the other being Scuba Life. But I think the 120s is going to push Liquid Blue over the top.

 

[BRT]

An AL100 is quite a bit more air than an AL80 even at 3000. An HP120 is a lot more air. Question is do you need that much to do the bottom time the dive op is going to allow. A friend that dives with us in Coz gets the biggest tanks he can so he can stay with us as long as he can. We dive AL80's because they last long enough to stay with everybody else on the dive.

 

[Carlos Danger]

That is actually one of two shops I am deciding between.... the other being Scuba Life. But I think the 120s is going to push Liquid Blue over the top.

IMHO Aldora are one of the top comprehensive operators on the island, so might consider giving them a look as well; if you haven't already done so. They do their own air fills, and exclusively use Steel HP 120s and Steel HP 100s for their boat dives. They also have a dedicated dive-focused Villa just north of town with daily pickup/dropoff + shore diving, and also offer some unique trips to areas that most other ops do not typically support.

Aldora Divers

Trip Report: Aldora/Villa Aldora/Food/Modified Bag Drag

 

[rongoodman]

Even without the extra gas, the 120 is worth it because of its nicer buoyancy characteristics.