Just ordered new tanks - anything to note?

[Barnaby'sDad]

I have a couple of those. Great tanks overall. They are big and heavy, but not really an issue in the water. If diving with a group, you may need to ascend well before your air is close to exhausted. If others are using 80s, you might be able to use the same tank for two dives.

The only thing to be aware of is the diameter. These are 8” where the most common are 7.25”. Usually not an issue, but you might just want to ensure that a charter can accommodate 8” tanks. The only time that might be an issue is if they use fixed Roll Control racks. I use the adjustable ones on my boat, and have them set in between. Tight fit for my 8”tanks, and a loose fit for the 7.25” tanks. Just not loose enough that there is a risk of them coming loose.

To me...that is one of the biggest perks for big tanks. Even being a bit of a gas hog, I can easily get two good length dives on a shallow profile (shore diving) out of an HP100.

On the 8” tanks...as was said...you will run into ops that have tank holders for 7.25” tanks. In the case of one that I dove with (Rainbow Reef), they had a few spots dedicated for larger diameter tanks, so it wasn’t a big deal.

 

[iyakonboats]

You actually will carry more weight than a HP100 because the large steel tanks are more buoyant than the smaller ones, you need about 2lbs more weight with a HP133 vs a HP100.

When full, correct, due to the increased volume? But as the air is used, at a certain point (such as empty) the HP133 is 1.45lbs compared to -0.9lbs for the HP100?

 

[ChuckP]

Thanks for the note on numbering them for maintenance/issues, I didn't think about that, it'll make it easier in the long run. I'll also drill those holes in the boot. As far as the size and weight, compared to the 100cu, it was about 8lbs more, but this also means just carrying less weight too. I figured if we noticed 8lbs we should probably focus on different muscle groups in the gym or we're procrastinating too long to get into the water, but I also imagine going to side mount, something we're looking at, makes it just that much easier in the long run, right?

Now I did NOT know about the 8" concern, very good advice, I'll call the charters I've scheduled to ensure they can handle it.

Also, for the valves, is there any reason to get the black coated valve from XS Scuba?

Holy smokes, didn't see they were 133's.... That's big, really big.

LP 95's, HP100's even stretching it to HP 120's for rec diving is much more common - well including the Aluminum 80 of course

Seriously, if you're new to diving, not sure entirely what you're doing for the future, why not just some Aluminum 80's? They are half the price

 

[Manatee Diver]

When full, correct, due to the increased volume? But as the air is used, at a certain point (such as empty) the HP133 is 1.45lbs compared to -0.9lbs for the HP100?

I wasn't even factoring the weight of the gas. You have about 2-3lbs more gas weight, 8lbs more dry weight, and another 2lbs more lead as the HP133 is more buoyant. So you are about 12lbs heavier in dry weight at the start of the dive, and about 10lbs heavier at the end of the dive.

 

[Barnaby'sDad]

When full, correct, due to the increased volume? But as the air is used, at a certain point (such as empty) the HP133 is 1.45lbs compared to -0.9lbs for the HP100?

That is correct and what he was getting at. The HP100 is still negative when empty. The HP133 is 1.45lbs positive/buoyant.

You’ll have to do some trial and error to see what kind of weighting you need based upon how you’re diving the tanks. Ex. You start a shallow shore dive with a HP133...I doubt very much that you’re going to want to stay in the water to run it down to the point that it’s positive.

 

[iyakonboats]

That is correct and what he was getting at. The HP100 is still negative when empty. The HP133 is 1.45lbs positive/buoyant.

Ok, I see what I misread, I was thinking backwards, literally, with what the values meant, I'm working on too many things right now :-/

 

[iyakonboats]

Holy smokes, didn't see they were 133's.... That's big, really big.

LP 95's, HP100's even stretching it to HP 120's for rec diving is much more common - well including the Aluminum 80 of course

Seriously, if you're new to diving, not sure entirely what you're doing for the future, why not just some Aluminum 80's? They are half the price

I am not new to diving, a long hiatus, and only recently got certified (grew up in S. Florida so I learned but was too poor to get certified when I was younger). Both my wife and I are going to get our AOW here soon, we plan on venturing further with this to DM and, way later down the road, instruct as a "retirement job", but we've got a long, long time before that.

 

[Barnaby'sDad]

Ok, I see what I misread, I was thinking backwards, literally, with what the values meant, I'm working on too many things right now :-/

It’s all good. They’re beast tanks. The biggest that I’ve used (capacity wise) are HP120’s. I’m sure you’ll get plenty of good use out of them.

 

[iyakonboats]

It’s all good. They’re beast tanks. The biggest that I’ve used (capacity wise) are HP120’s. I’m sure you’ll get plenty of good use out of them.

They had 149cu, but I kind of figured that was just overkill

 

[johndiver999]

It sounds like you may have NOT actually bought those tanks. If you have bought them, then fine.. but I would NOT buy new tanks like that. Instead, spend more and get the cold dipped galvanized tanks. They will quickly be ugly and gray, but you will be much happier with non-painted tanks.. It is worth the extra $$.