diving with a pony vs doubles

[in_cavediver]

Originally Posted by CompuDude

Sure, if that's what you end up doing.

But sometimes you plan to do two but only end up doing one.

And if you had planned to do one long extended dive, you're paying for double fills even if you could have done the same dive with one HP130.

And if you planned to do one very long dive, and had to shorten the dive for some reason, you still get to pay for two full fills to refill even 1000 psi to top off the tanks.

A short skills dive that lasts 1/2 hr in shallow water now costs 2x the price to top off your tanks for the next real dive... even though you only used 300-500 psi, shops don't care... they hook up doubles, you pay for 2 fills.

Ditto for boats. If you're diving rec profiles on boats with on-board compressors, generally they are going to charge you double for fills whether you use all the gas or not. If you're squeezing 2 dives per fill out that will help, but there are boats that charge a flat a rate for the day's fills and then double that if you have doubles.

There are tons of scenarios that this would apply to... it's not really that tough to figure this out.

Unless you're paying for gas by the cf, refilling doubles is going to cost double what it costs to refill a single tank... so unless you genuinely need 2x the gas, you're paying a lot more. Again, not large amount of money until you start looking at Nitrox, but even with air it adds up if you're doing it a lot.

To be fair, you have to decide you want 'full' tanks. In many cases, where shore diving and shallow, starting with less than full tanks is not a problem. The only case this would be an issue if boat diving. Where I am at (and SP), its mostly shore diving so this is a moot point.

Also, you ask the question of filling doubles vs singles. If you did 2 dives, you pay 2 fill regardless if doubles or singles. If you do three dives, it might be 2 fills for doubles and 3 fills for singles.

As for your boat example with the flat fee - I have never heard of that. Really weird. Might make want to go to independents just to piss them off......

Far to many scenarios to say one is clearly superior to the other. It all depends on how/where the diver dives.

[in_cavediver]

I have had the pleasure of seeing several people learn doubles and I can say confidently those with decent mentors tend not to have much issue. ScubaPete inherited information about basic setup to where he didn't have to do much with tank/band position, gear configuration etc. It was just set at a starting point (which is very close to the optimal point) and he went out. The several people I have seen with this kind of 'kickstart' all thought the transition was easy. Those who 'learned' the hard way had a rougher road.

Doubles can be a PIA to learn to dive. They can also be a smooth easy transition as well. (I personally had zero issues whatsover)

Originally Posted by Jack Hammer

Just because some people have never had a balance/trim issue with doubles doesn't negate that many other people have had those issues. I've personally talked with more than a few experienced and accomplished divers that ended up turtling on the bottom the first time they used doubles. I've seen some people nail the setup on the first try. I was somewhere in between. When I first dove it was easy, then I made a few insulation and weighting changes and it went a bit wacky.

The big advantage for me with doubles is when I do dives to different depths. I can do an hour long dive in teh 80' range followed by a an hour long dive in the 40' range and have plenty of gas for each. With singles, I wouldn't have enough gas for that length on the first and would end the second with a lot left over.

[Scuba Pete]

Originally Posted by in_cavediver

I have had the pleasure of seeing several people learn doubles and I can say confidently those with decent mentors tend not to have much issue. ScubaPete inherited information about basic setup to where he didn't have to do much with tank/band position, gear configuration etc. It was just set at a starting point (which is very close to the optimal point) and he went out. The several people I have seen with this kind of 'kickstart' all thought the transition was easy. Those who 'learned' the hard way had a rougher road.

Doubles can be a PIA to learn to dive. They can also be a smooth easy transition as well. (I personally had zero issues whatsover)

The only issues that i had where with a certain somebody hitching a ride on my bands everytime I dove with them. Maybe that is why I swim so fast now.

[Scuba Pete]

I guess I should say that from the experience that i have had and the diving that we have done and do that doubles are no problem, and it makes sense to me to dive them in lieu of having a pony. I suppose that diving a pony would make more since to me if i were diving the kind of dives that would warrant the pony instead of doubles. I am not sure what kind of that diving is as I have not done it. I have been diving on the east coast where they seem to be popular. I can see if someone wanted complete redundancy, i do agree that a pony is more redundant than doubles. I think of a pony like sidemount. 2 complete tank setups. I think a pony/doubles depends on why you are wanting to dive them. If you are going deep >90ft and want a backup i think doubles are better suited. If you are staying shallow<60ft and want something like a buddy bottle/seperate air source then a pony may be an option to consider. In recreational diving you should always have a buddy as a seperate air source and can safely ascend to the surface. So as a positive with pony bottles i would say that it is a complely seperate air source.

[in_cavediver]

What, you are not my private 'poor man's DPV' anymore ??????

Originally Posted by Scuba Pete

The only issues that i had where with a certain somebody hitching a ride on my bands everytime I dove with them. Maybe that is why I swim so fast now.

[MxDiver]

I remember doing that to my wife once, her buoyancy control wasn't all that good back then (first trip after she got her cert) so I grabbed her BCD to help her stay with the group. It was a drift dive and I didn't make much of it until I commented how the current seemed to carry me better on that particular dive and how I did not have to kick as much; that's when she casually mentioned how she couldn't stop kicking to keep up with the group on the same dive.

[cummings66]

Originally Posted by Scuba Pete

If you are going deep >90ft and want a backup i think doubles are better suited. If you are staying shallow<60ft and want something like a buddy bottle/seperate air source then a pony may be an option to consider.

When I'm going deep with doubles I take an AL40 with me for backup. Easy and gives me practice. I want multiple options in case everything goes wrong at once. That's why I use a drysuit, liftbag, and a BC. It's all about the options.

[Scuba Pete]

Originally Posted by cummings66

When I'm going deep with doubles I take an AL40 with me for backup. Easy and gives me practice. I want multiple options in case everything goes wrong at once. That's why I use a drysuit, liftbag, and a BC. It's all about the options.

Deep is a relative term. I would also want to carry some sort of stage bottle with me when i go deep as well. But in the context of the discussion I had left that out.

[Tassie Diver]

Originally Posted by Scuba Pete

How is that any different than using 2 tanks on 2 dives. You are actually paying the same amount for air. I can get 2 or 3 dives from my doubles so i think that is an invalid point.

The most expensive part (for a shop) of doing a fill is paying the person who fills the tanks. Manifolded twins only require the same amount of labour as a single tank. The actual equipment and filter depreciation costs are slightly higher for twins as there is more air going through.

So cost for filling twins should not be twice that of singles but maybe 1.5 times?

Cheers

TD.

[CompuDude]

Originally Posted by Tassie Diver

The most expensive part (for a shop) of doing a fill is paying the person who fills the tanks. Manifolded twins only require the same amount of labour as a single tank. The actual equipment and filter depreciation costs are slightly higher for twins as there is more air going through.

So cost for filling twins should not be twice that of singles but maybe 1.5 times?

Cheers

TD.

Right.

So how's that working out for you?