PST 104's vs Worthington 130's

[rjack321]

Overfilling won't be a problem. I do my own fills, and my shop owner doesn't blink an eye at filling his hp100's to 4000.

Rjack, I dont know all the details just yet, but I know he encourages his students to all be on the same size tanks, I'll have to ask him specifically why he recommends that. I know one reason he has mentioned, was being able to do 2 tech 1 dives on the same charter, without having to bring stages or another set of doubles.

2 dives off one set of doubles is admirable, but you can do the same thing with a bottom stage and also have the capabilty to change gases. And have less weight to lug around too. E.g. a 160ft dive on mix followed by a 2nd recreational dive on just nitrox. You're a big guy so the weight isn't a terrible burden muscularly. But even though I'm 70lbs lighter your lumbar disks are built just like mine.

If you can, try to borrow some of these likely doubles and see which ones you prefer. Sounds like there are various sets in your neighborhood.

 

[Jimmer]

2 dives off one set of doubles is admirable, but you can do the same thing with a bottom stage and also have the capabilty to change gases. And have less weight to lug around too. E.g. a 160ft dive on mix followed by a 2nd recreational dive on just nitrox. You're a big guy so the weight isn't a terrible burden muscularly. But even though I'm 70lbs lighter your lumbar disks are built just like mine.

If you can, try to borrow some of these likely doubles and see which ones you prefer. Sounds like there are various sets in your neighborhood.

I can likely track down a set of either to try out, and I likely will. I do have a pretty good idea of the weight and how much lugging is involved, as my first set of doubles was a pair of Faber 108's. I sold them off partially because I was a bit strapped for cash at the time (tuition seemed more important at the time), but also because I was getting paint chips and some spot rusting, and I haven't seen too many Fabers in the area that dont look like hell after a couple season, so I decided my next set would be galvanized.

 

[MXGratefulDiver]

Jimmer, for someone your size the 130's would be a good choice. I've dived the HP100's and they're a very nice tank ... but if you ever decide to go beyond Tech 1, you're going to find that they're not adequate capacity for deeper (180+ foot) dives and you'll only end up getting a bigger set anyway.

The 100's trim out completely different than the 130's and rather than trading up or having to get used to a different setup, I'd say just go with doubles that'll accommodate a path to full trimix.

Another point worth mentioning is that for doubles you'll probably want to purchase two tanks that were manufactured at the same time to "size match" them. I've seen significant differences in height in some tanks that are supposedly the same size ... especially the PST104's ... up to 3/4" or so. They'll band up OK, but they look kind've funky.

Just a coupla things to keep in mind when you buy ...

... Bob (Grateful Diver)

 

[texdiveguy]

.................. you're going to find that they're not adequate capacity for deeper (180+ foot) dives and you'll only end up getting a bigger set anyway.

In reference to HP100 not being adequate for divers beyond 180ft....this is not true. The better preference/IMO to those would be LP85's with an o/f to 3600-3800psi (in the technical dive circles/community it is rarely hard to get an o/f even on the fly) which are quite adequate for much deeper single dives. In terms of our OP and his size he may well find the 130's to his liking and those would offer him a full range of diving now and future. For smaller///older divers a quality set of smaller tanks such as LP85's with an o/f are quite adequate for o/w trimix dives well into the advanced trimix range and even o/h trimix dives well past 180ft.. I am by no means suggesting smaller doubles for our OP as his size will possibly allow him the large end of the spectrum of tank sizing.....get what works for you....try several sizes prior to purchasing if at all possible.

 

[DA Aquamaster]

Double 100's will get you through normoxic trimix, and to be honest if you need to go deeper/longer you can always sling an AL 80 as a stage with bottom mix.

Also, it is no fun to drag along double 130's if the majority of your dives would be handled well enough with double 100's. Hauling double 130's up the boat ladder in 5-6 ft seas is not much fun at all if you really did not need the extra gas.

And if you go the full trimix route, you will end up with multiple sets of doubles or you will find youself with your one or two sets of doubles containing the wrong mix on a regular basis. So get what ever will work best for the majority of your technical diving rather than handicapping yourself by going overboard and configuring for the most extreme half dozen dives you will ever do.

 

[texdiveguy]

Double 100's will get you through normoxic trimix, and to be honest if you need to go deeper/longer you can always sling an AL 80 as a stage with bottom mix.

Great addition of info about the slung traveling bt stage.....I carry one on occasion with my LP85's on hypoxic trimix dives, thought the doubles o/f have plenty of capacity for deep hypoxic profiles.

Also much agree about getting to start what works best for you and the 'majority' of your projected dives......bigger is not always better.

 

[rjack321]

My lp85s are also my favorite doubles for anything down to 200ft. I have used hp130s and they also work, but when you struggle out of the water with enough gas for a second big dive still in them, you start to question the wisdom of carrying all that.

 

[Jimmer]

Anyone know how the old 3500 psi hp100's compare to current Worthington X7-100's for trim, weight, buoyancy etc? I don't know anyone locally that has a set of the newer 100's, but I do know one guy with a set of the old 3500psi tanks that I could borrow to try out.

 

[rjack321]

Anyone know how the old 3500 psi hp100's compare to current Worthington X7-100's for trim, weight, buoyancy etc? I don't know anyone locally that has a set of the newer 100's, but I do know one guy with a set of the old 3500psi tanks that I could borrow to try out.

The newer 3442psi worthington's are slightly heavier (about a pound more negative each). They trim out the same. The older 7/8" valve 3500psi tanks are fine except: 1) they are a bear to tumble through the tiny neck 2) the genesis manifolds almost all have a funky angled outlet which creates suboptimal hose routing.

 

[Jimmer]

The newer 3442psi worthington's are slightly heavier (about a pound more negative each). They trim out the same. The older 7/8" valve 3500psi tanks are fine except: 1) they are a bear to tumble through the tiny neck 2) the genesis manifolds almost all have a funky angled outlet which creates suboptimal hose routing.

Well if they trim about the same, I think I'll try borrowing a set and see if I like them, before I go and do something foolish like drop a bunch of money on new Worthingtons. I'm going to try to track down a set of the X8-130's to try as well.

Also, this set of the 3500 psi tanks has a Dive Rite manifold on it, so no weird angles to deal with.