having some trouble deciding on tank size

[jashaw]

I will be taking technical foundations this coming spring and will need a larger capacity steel tank. I have been particularly interested in either LP120 or HP120 sizes. What are some pros/cons on the pressure rating differences?

Thanks,
Jason.

 

[tbone1004]

none really on the pressure difference, but the difference in physical size between those two is rather large...
6-8lb weight difference, 7 vs 8 inch tank diameter and adding another inch and a half to tanks that are already VERY long.
The HP120's are 2 inches longer than standard AL80's which are about as long as most people can take. The HP120's are a bit heavier in the water than the LP's which is good for most things.

Don't know how tall you are, but the 120's are REALLY long tanks. I use them for sidemount and back singles, and when buddies have used them, they have problems sitting down. I'm fine, but not so much with them. HP100's are really good tanks, as are LP95's, both of which are much more common than the 120's, especially on the used market

 

[jashaw]

I am 5'10". I would like to stay at least with an HP100. But would rather have a 120 as previously stated.

 

[tbone1004]

all I can say is try before you buy, especially if you plan on doubling them up.
Check the 130's out. They're shorter than the 120's, which is much better, only a few pounds heavier, and still big

 

[lsorenson]

What are some pros/cons on the pressure rating differences?

Pressure rating??? IMO, no matter the shop, you will always get a good fill on a LP's... I seem to have problems getting 3400 in a HP consistently and ask for 3000 in the LP's. I have 100hp's and 120lp's. 100hp work well for me in any type of OW leisure diving... I use the 120lp's when diving for Meg teeth off the NC coast... Lots of huffing and puffing when your looking for little treasures!

The LP's can cause you some problems on "some" boat trips depending how they are rigged for carrying tanks e.g. if your tying them up with bungees, then no problem with either tank but IF the boat is outfitted to carry only 7" tanks (HP and ALUM) then you will just lay your stuff on the deck...

My 120LP's are pretty big fatties but then I am 6'1 @ 250...

But I am sorry because I don't know which tank would fit your bill for Tech diving...!

Best to you, lee

 

[mpgunner]

Take a look at the HP119's. Nice size/weight balance.

 

[Graeme Tolton]

I'll second the 119's. I am 6'6" and dive double 119's... great tanks with lots of gas! OTOH, 130's are very similar, just a touch longer with more gas... if you are buying new, the cost difference is minimal between 119 and 130.

 

[RJP]

all I can say is try before you buy, especially if you plan on doubling them up.

^This.

If you're taking "technical foundations" (whatever that is) sounds like you're heading down the tech route, where doubles is not far around the bend.

I dive double 119's and love 'em, but they are heavy. I'm 6'2" and 180lbs and the size/trim characteristics are perfect for me. Overall they ideally suit the deep, salt water wreck diving I do here in NJ.

 

[PfcAJ]

I think it depends on the type of diving you want to do. If you're headed down the tech route, double lp120s are pretty hauss and not needed for almost any dive. I would not want to haul those on a pitching boat ladder.

The following is a generalization that works pretty well:

Cave diving - double 104s/ hp130s w/ drysuit
Warm OW or warm shallow cave- double al80s w/ wetsuit
Colder OW - double hp100s w/ drysuit.

Clearly, different setups can be considered, but that seems to be a winning combo for a lot of folks. Just for a comparison, al80s plus an al80 stage roughly equals double 104s as far as gas capacity, but it a lot more reasonable to move around on a boat.

 

[Graeme Tolton]

I think it depends on the type of diving you want to do. If you're headed down the tech route, double lp120s are pretty hauss and not needed for almost any dive. I would not want to haul those on a pitching boat ladder.

The following is a generalization that works pretty well:

Cave diving - double 104s/ hp130s w/ drysuit
Warm OW or warm shallow cave- double al80s w/ wetsuit
Colder OW - double hp100s w/ drysuit.

Clearly, different setups can be considered, but that seems to be a winning combo for a lot of folks. Just for a comparison, al80s plus an al80 stage roughly equals double 104s as far as gas capacity, but it a lot more reasonable to move around on a boat.

Based on the OP's location, he will most likely be diving in cold water most of the time. Any tech diving done in cold water is done in a drysuit. That being said, Steel tanks are usually the best way to go, because the weight difference of AL tanks is made up in some other form of ballast, such as a heavier SS backplate or lead. Starting out at tech, most divers wont be dealing with multiple sets of doubles. I would recomend talking with your future instructor and find out what dives you would be doing in your training to become a tech diver. From there, you can figure out how much gas you need to be able to carry, based on simple calculations the instructor can help you with. Everyone has different needs, but IMHO, for cold water diving, you want steel tanks.