HP Tank

[Slym]

Hey guys,

I am going to a demo day with my dive shop on Sunday and was going to rent my stuff, I am still debating whether I should rent a HP100 or an AL80 as I will be doing two dives I estimate.

this is what is happening if you are curious... will be a fun day!

Anyway what do you guys think? 2 AL or 1 HP?

 

[Jim Lapenta]

What's your SAC rate? What's your RMV for dives going to be?
If the HP 100 gets a full fill it's still only 20 cu ft more than an al80. To say how much gas you should take we need to know your SAC rate, the planned dive profiles, are you diving with a buddy and using Rock Bottom, 1/3 rds, 1/6 ths, or some other gas plan?
If the HP100 only gets filled to 3000 PSI you then only have 87 cu ft. in it.

 

[Slym]

Right I forgot the important information...lol

I only have 12 dives logged, and am not too great on air consumption yet an AL80 lasts me about 35 minutes at 60-50 feet, not too sure how deep welland scuba park is but I don't think I'll be going more than 50 feet. I called the dive shop and I think they will only have 130's in stock (and a ton of AL80s) I drive a small car so I don't really wanna have to get two tanks if I can get a big enough single.

I'll be with a buddy and probably turn the dive at 800 psi so we can go for our safety stop if using AL80s.

 

[rhwestfall]

well, I know where NOT to be Sunday.....

 

[tursiops]

Given your parameters, you need two AL80s, or two short dives on the single 100. I hope you understand why.

 

[Got2Go]

Based on what you posted...I'd say 2 AL80s...unless you want to cut your dives short.


Edit: Yeah, what he said above... :/

 

[Fogest]

well, I know where NOT to be Sunday.....

I am doing my checkout dives next weekend at this same park. So probably another day you know where to not be

@Slym I would bring two tanks with you. 2 AL80's. There is not a close place to fill at Welland Scuba Park.

 

[JohnN]

Right I forgot the important information...lol

I only have 12 dives logged, and am not too great on air consumption yet an AL80 lasts me about 35 minutes at 60-50 feet, not too sure how deep welland scuba park is but I don't think I'll be going more than 50 feet. I called the dive shop and I think they will only have 130's in stock (and a ton of AL80s) I drive a small car so I don't really wanna have to get two tanks if I can get a big enough single.

I'll be with a buddy and probably turn the dive at 800 psi so we can go for our safety stop if using AL80s.

So I've never had a problem with having too much gas on my back. An Al80 and HP100 weigh about the same out of the water, are about the same size and the HP100 is still negative when close to empty.

Seems like a no-brainer to me. What was that question again?

 

[rx7diver]

I am going to a demo day with my dive shop on Sunday and was going to rent my stuff, I am still debating whether I should rent a HP100 or an AL80 as I will be doing two dives I estimate. Anyway what do you guys think? 2 AL or 1 HP?

Slym,

Don't forget weighting considerations: With your completely full HP cylinder and completely empty BC, can you remain substantially positively buoyant at the surface in your full gear but without your weight belt? If not, then maybe you should not dive that HP tank. Or maybe you should make other gear choices (e.g., wear a 5 mm wetsuit instead of a 3 mm, etc.).

Safe Diving,

rx7diver

 

[CT-Rich]

I would say really to 2 questions get answered on this outing. First, what is it like to dive with steel tanks? Steel tanks weigh more than AL, but you require less lead. Personally I like the way they trim when in the water, especially towards the end of the dive. As a purchase they are more expensive.

Second, is getting 25% more air of value to you? If you are an air hog and don't want to be the first guy out of the water, that may be a good reason. If you have a low SAC, then it might not because cold or buddies might get you out of the water first.

Aluminum tanks are everywhere, so you will never worry about adjusting your weights and straps. If you use steel and need to switch over to AL, you will have to make changes on your rig with every time you switch between them. Not a huge thing, but it can be annoying.

Finally how are you carrying the extra weight of the tank? Tanks stick out from your body so they make you less stable on the surface. If you weigh 120 lbs a giant tank might be a poor choice.