Twin 72’s vs HP133

[rx7diver]

I have an HP 120 now which I could beg for a light cave fill. IDK what it becomes at 4 grand? ...

We ran our HP cylinders (3,500 psig PST cylinders) to 4,000 psig when I lived near the Great Lakes. Of course, these cylinders wear 300 Br. DIN valves. You'd think you're getting 139 cu ft (= 4,000 * 122/3,500) with a 4,000 psig fill in a HP120, but, because of the compressibility factor of air or nitrox, you're getting a bit less. (DGX has a good write-up on this, IIRC.)

I have heard that some people would run the OMS (Faber) LP125 to 3,500 psig, which would provide 165 cu ft (= 3,500 * 125/2,640), if you ignore compressibility. I don't know if I would be comfortable having the LP cylinder routinely filled this close to the test pressure (= 4,000 psig = 2,400 * 5/3), though.

 

[happy-diver]

I don't know what it is about fins in the dead zone, but that is why you install a chest strap

Bumble stumble pull yourself along the bottom or drop in and pull yourself to the bottom
and when you're comfy down there somewhere laying on your back wedged in between a
rock and a prickly place you put your fins on get your breath back and when you are good
you go and on the way out, fins strapped to chest, never on your feet, never in your hands

Have you got the paperback with the yellow cover
NO FINS TO BE WORN IN THE INTERTIDAL ZONE!

They should enact it into a council ordinance now!

 

[happy-diver]

You could sidemount 72s and send one up with the bag when the surge is bad. Easy to walk out with the other.

Come on man how about you think about it and realise a helicopter extrication is the most practical

 

[BoltSnap]

They have 20L steel tanks in Germany, be a real man and get a doubles kit of those 20L Tanks!!!

 

[Tracy]

Steel 72 doubles are very light and comfortable to dive and walk around in. When I get back in the country, I am happy to throw some different sets on the scale to compare to other tanks if you would like. I have several hp133s and way too many 72s.

 

[rob.mwpropane]

@Eric Sedletzky as you know we dive for oysters here. It's not deep (18' max) but there is a good bit of current, low viz, cold water. I always dive a set of double 85's. I like the redundancy. I don't have to climb back up to switch tanks. I actually have people feed me and give me water at the ladder before going back down for another basket.

Now this is from a boat so a little easier. I've done a shore dive with doubles a good bit and it is a bit of a pain to get past the break, but it's possible.

I dream of setting up a set of 72's for the dive, but the 85's work great.

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[Eric Sedletzky]

@Eric Sedletzky as you know we dive for oysters here. It's not deep (18' max) but there is a good bit of current, low viz, cold water. I always dive a set of double 85's. I like the redundancy. I don't have to climb back up to switch tanks. I actually have people feed me and give me water at the ladder before going back down for another basket.

Now this is from a boat so a little easier. I've done a shore dive with doubles a good bit and it is a bit of a pain to get past the break, but it's possible.

I dream of setting up a set of 72's for the dive, but the 85's work great.

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Oysters sound so good!!
We don’t have anyplace around here that I know of (yet) to get oysters. The ones they farm in Tomales Bay are not native to here, they are originally from Washington State.
I get random people coming up to us on the beach slobbering all over themselves over the urchins and they are welcome to take as many as they want, but to be honest uni doesn’t even come close to oysters for me.
I’m jealous!

 

[Eric Sedletzky]

I don't know what it is about fins in the dead zone, but that is why you install a chest strap

Bumble stumble pull yourself along the bottom or drop in and pull yourself to the bottom
and when you're comfy down there somewhere laying on your back wedged in between a
rock and a prickly place you put your fins on get your breath back and when you are good
you go and on the way out, fins strapped to chest, never on your feet, never in your hands

Have you got the paperback with the yellow cover
NO FINS TO BE WORN IN THE INTERTIDAL ZONE!

They should enact it into a council ordinance now!

I don’t know what the agencies say about shore entries or big surf entry now days. I’m interested to know how PADI says to do it and how GUE says to do it; if there is a written protocol that must be followed. I know NAUI at one time had a class on large surf entry which was probably Southern California centric since they seemed to do a lot of that around Laguna Beach up to Malibu.
Socal is where NAUI started anyway. I have no idea what the content was or what was standard proceedure for entering with fins on it off or if you clipped them off, or where they were clipped off on your person.
Everyone has there way to address rocks and getting past the surf zone. When I was younger and more flexible I had no problem marching in waist or chest deep water with moderate surf and donning fins in the water.
Now it’s tough and a good way to lose fins and struggle and possibly get hurt.
I’ve had to adapt.

 

[MarkA]

They have 20L steel tanks in Germany, be a real man and get a doubles kit of those 20L Tanks!!!

20L Eurocylinder Twinset - DirDirect

O2 clean steel 20L Eurocylinder Twinset with high-quality BtS marine grade stainless steel twinning bands and reliable manifold with an isolator.

www.dirdirect.com

 

[lexvil]

Crazy surf, I just don’t go in but totally a judgment call. I’m not crawling in or out.

The original question; pair up a few 72’s, they will likely balance better than a giant single and be less cumbersome as you deal with the surf and rocks and more importantly they will just look cooler! Those giant singles look like RV propane tanks.