Steel vs aluminum 40 for redundant: which is better?

[grf88]

We have to look holistically at the entire system including the integrated team, not just at individual pieces of gear. Your dive buddy provides your full redundancy. An isolation manifold maximizes your options for preserving breathing gas under the most common failures.

While in theory a manifold does represent a single point of failure, in practice you're more likely to be struck by lightning than to lose all your back gas from a broken manifold. What seems to make sense in an online discussion doesn't necessarily work well in real diving.

The isolation valve does not have to be broken it just has to be stuck and that is much more frequent than a lightning strikes. Team diving is fine with a team that trains together which is usually not the case in a lot of recreational diving when you may not know your buddy or have never seen them in a emergency. To rely on your buddy for your emergency gas in a situation like that is asking for trouble.

 

[billgraham]

I think the Al 40 is more what you're looking for here.

 

[broncobowsher]

The AL40 will get you through the summer.
But seriously consider a set of doubles for the future. You can get use out of the doubles instead of un-used tag along gear.

Few years back did the U352 and had a discussion with a guy with doubles. Diving recreational profiles. Typical double dip boat trip. His gear is set up once, before he gets on the boat and doesn't change anything the whole day. The first dive, has a whole second tank as reserve. Second dive, has not only the reserve from planning a single tank, but whatever is left over from the first dive. There is no fumbling about swapping tanks on the boat between dives. At this point you are only dealing with 2 tanks (as doubles) and not 3 tanks (two singles plus the slung). It is a very smart way of dealing with it. Dealing with Nitrox? Doubles filled and the mix doesn't change. 2 seperate fills, blender having a bad day and they test a little different, another thing to change while between dives. Or just pick up where you left off from the last dive.

 

[mr_v]

The AL40 will get you through the summer.
But seriously consider a set of doubles for the future. You can get use out of the doubles instead of un-used tag along gear.

Few years back did the U352 and had a discussion with a guy with doubles. Diving recreational profiles. Typical double dip boat trip. His gear is set up once, before he gets on the boat and doesn't change anything the whole day. The first dive, has a whole second tank as reserve. Second dive, has not only the reserve from planning a single tank, but whatever is left over from the first dive. There is no fumbling about swapping tanks on the boat between dives. At this point you are only dealing with 2 tanks (as doubles) and not 3 tanks (two singles plus the slung). It is a very smart way of dealing with it. Dealing with Nitrox? Doubles filled and the mix doesn't change. 2 seperate fills, blender having a bad day and they test a little different, another thing to change while between dives. Or just pick up where you left off from the last dive.

After diving CC, I am contemplating baby doubles for these exact reasons for rec dives. 50LPs aren't that hard to haul around while giving you redundancy you need.

 

[tursiops]

Insults are taken, not given.

You haven't even got the quote right -- it is Offense not Insult -- and as you have stated it, it is an entirely wrong statement. You're an idiot. there, I just insulted you. But only to make the point. You may reject it, ignore it, disagree with it, but I've insulted you none the less.

 

[tursiops]

I'll flip your question back at you: why does someone always advocate for a pony bottle when there are better solutions?

There are several options for redundancy and with each there are pros and cons, including the ease and cost of implementation. It is a sliding scale...not a black-and-white "redundancy or not." Suggesting the pony is the easiest and least costly way to achieve redundancy, versus more elaborate and costly and difficult to manage and requiring perhaps some training and certainly some practice. That's why the pony is the first recommendation. The "perfect" solution is not always the "best" solution.

 

[broncobowsher]

After diving CC, I am contemplating baby doubles for these exact reasons for rec dives. 50LPs aren't that hard to haul around while giving you redundancy you need.

I was the only one on a CCr on the boat. Just getting a few easy dives in to build time. Overkill for dive, but a good dive to build CCR time on.

 

[mr_v]

You haven't even got the quote right -- it is Offense not Insult -- and as you have stated it, it is an entirely wrong statement. You're an idiot. there, I just insulted you. But only to make the point. You may reject it, ignore it, disagree with it, but I've insulted you none the less.

When all fails, default to spellcheck and grammar.

Let me learn you something: "insult" and "offense" are synonyms. And no, my quote is not an "entirely wrong" statement. It is not the original, I agree.

 

[rob.mwpropane]

@coldwaterglutton NE diving is still sort of the wild west. I love it, but as you can see there's a lot of controversy about the way we / they dive.

I've seen independent doubles, ponies, manifolded doubles.. even a few SM. It all works fine if your son practices. Slinging a 40 and doing a gas switch isn't rocket science, but he should get some practice somewhere benign before the trip.

Good luck and have a blast making memories!!!!!

 

[rx7diver]

... But it's also why I take a 40L pony and not one of the smaller sizes. ...

You probably meant to write "40 cu ft" (rather than "40L").

rx7diver