Faber 3180 plus rated HP tanks ?

[Scared Silly]

What would the opinion be for the 3180 tanks in doubles with a dry suit? Im not quiet to the point of doubles but that is my plan. Will I regret having 3180 tanks?

Read this post: #6

 

[Roman_66]

Do the math and you would find that as set of doubles they are bricks:

-14 lbs full x 2
-4 lbs bands and valves
-3 Al back plate

I think math should be done based on Empty (or 500 PSI) tank buoyancy.
So for M100DVB it will be (6.7 x 2 ) + 4 + 3 = 20.4 lb
On the start of dive you always overweighted at least by air weight in doubles, which is about 12 -14 lb.
With working wing 30lb you should not have any issue to control your buoyance, even you took 4 pounds more, as most people do.
5mm wet suit will add more issue here - about additional 8lb positive on surface, which will be only about 2 lb on 60ft deep.

 

[Scared Silly]

I think math should be done based on Empty (or 500 PSI) tank buoyancy.
So for M100DVB it will be (6.7 x 2 ) + 4 + 3 = 20.4 lb
On the start of dive you always overweighted at least by air weight in doubles, which is about 12 -14 lb.
With working wing 30lb you should not have any issue to control your buoyance, even you took 4 pounds more, as most people do.
5mm wet suit will add more issue here - about additional 8lb positive on surface, which will be only about 2 lb on 60ft deep.

No the math should be done when full and when one is the least buoyant that is when one is at their deepest depth (or really after about 50-75 feet). Then plan for a BCD or drysuit failure and figure out how to get yourself to the surface. As you note a wetsuit at depth will have negligible buoyancy.

Then do the same math at the surface without you in your rig. That 30lb wing is not going to keep a 35lb rig afloat at the surface.

So what you are thinking is going to leave you and your gear on bottom sucking water …

 

[Roman_66]

No the math should be done when full

Depends what we are calculating
You should be ligtly (around 2-4 lb) negative with 500 PSI on surface, only to be able to go down or to be able to keep yourself on 10-15ft deep.
Air in doubles weights about 14 lb.
So on start of a dive with doubles you are about 18 lb negative.
Sentence about 35 lb negative may confuse. 35 lb might be weight of equipment, but not buoyance in water.
If one of your buoyance works (wing or dry suite), you will not have issue to go to surface + you can catch and use buddy with his/her two buoyance systems.
In worse-worse case you can go away half of your air and go to surface using just fins (14/2 + 4 = 11 lb).

But may be I missed the discussion point. What do you suggest ?

 

[Scared Silly]

But may be I missed the discussion point. What do you suggest ?

Yes, you have missed the points, as in multiple. Think about when Davey Jones comes a calling not when you are dreaming of mermaids . At this point I would suggest you do an intro to tech course and learn some fundamentals as there are many many red flags in your posts.

 

[Roman_66]

At this point I would suggest you.

I asked what you actually suggested to topic started, except not fully correct math
I didn't ask suggestion, as Fundamental already done.
When arguments are finished, you can move a discussion to be personal
Other replies went to PM to prevent punishment

 

[Irish1957]

yes,i believe you will.

 

[Jamey K]

In answer to "imjustdave". I was diving a single older heavy Faber 3180+ with dry suit with 14 pounds of lead. It was perfect. Now I'm diving dual side-mount 3180+ but with a very minimal harness and zero extra lead, because the extra tank adds the 14 pounds plus my back plate only weighs two pounds and the extra regulator weights a few pounds. So by adding just enough air to my dry suit to keep me warm, it's perfectly balanced. It really all depends on your rig. If you are diving a heavy steel backplate, then I would say "no" this is too heavy. If you are diving a minimal dual sidemount rig, then I really like this setup. When I dive dual tanks with backplate and manifold, I use the newer Faber 3440. I think they are about 6 pounds lighter each. Again, it all depends on what you are doing. Experiment (cautiously), until it feels just right. But don't let anyone tell you one thing or another is not good. You will find out for yourself, but again, just experment in baby steps and see what works for you. (Jamey)