Zac3G:
I'm just wondering if anyone has an opinion on witch Pony Tank setup is best. There is the style without a hose like the H2Odyssey that goes on your BC, or the type that goes on your tank with a hose and octo. type regulator. I can see pluses and minuses for both. I'm getting ready to buy one and would like to hear any input you may have... Thanks...
Hello,
Just thought I'd add my view to the mix!
WHAT I BOUGHT
I have decided to use a backmounted 13 cu. ft. pony bottle with a traditional 1st stage and octopus.
TYPE OF DIVING I DO
I dive mostly in the Caribbean and a little bit in the Northeast. The boats in NJ require at least a pony bottle, so I've been renting one when needed. I have no plans to perform technical, mixed gas, deco, wreck penetration, or cave diving, and would be fine purchasing additional equipment if I change my mind in the future. Other than the pony bottle, I do not own my own tanks.
WHY I WANT A BACKUP AIR SUPPLY
I don't have a regular dive buddy, so on all my dives, I'm paired with whoever on the boat is available. My "buddy of the day" may seem like a good communicator on the boat, but I've found that most buddies are not that good at staying nearby underwater or even at checking to see if you're okay underwater. This has lead me to conclude I need to be more self-reliant, and for me, part of that is having a backup air supply.
SELECTING A BACKUP AIR SUPPLY
I calculated my air consumption rate and found that the Spare Air doesn't have enough capacity for me to return to the surface, let alone do a safety stop. While 19 cu.ft. would suit me pretty well from 120', even allowing me to do a safety stop while breathing more rapidly from stress, I calculated that a 13 cu. ft. would also work in most cases. My calculations tell me that if I came up short, I would have to omit or shorten my safety stop, but could make it to the surface. The 13cu.ft. is also easier to pack in my luggage than a 19cu.ft.
I looked at the H2Odessy Extra Air Source, but decided that a hand held 13 cu. in. cylinder would be unwieldy. Even if my air consumption rate allowed me a smaller cylinder, I'd rather be hands free. I'll be using my hands for my dive computer and inflator hose and want to minimize task loads - especially in an emergency.
So that left me with purchasing a pony bottle with normal 1st stage and octopus.
MOUNTING LOCATION
I decided to backmount my pony bottle. That keeps my setup simple and familiar. The bottle stays out of the way of my other front mounted gear, does not dangle below me, stays closer to the center of my body without blocking my weight belt or other releases, and, being next to my main tank, is more streamlined than front mounting. Given the type of diving I do, I also feel it is less likely to get snagged (okay maybe during the occasional swim-through). I realize that if a snag did occur, it would be harder to fix the problem by myself.
I feel that a back mounted pony bottle shifts around less than a bottle clipped to the front of my BC -- my two tanks (main and pony), become bonded to each other in a manner similar to having doubles. Since it doesn't shift, it's easier for me to determine a spot to put trim weights (left rear BC weight pocket or tank band - left side), which allows me to better control my buoyancy (less rolling to the side from the weight of the pony bottle). It's easier for me to maneuver as well. I sometimes like to hover close to the sand or even inverted so that I can peer under ledges close to the bottom. These common positions (common for me) would be made more difficult with a front mounted pony. Many times, I'm diving in marine parks where you're not supposed to touch anything ("take only pictures, leave only bubbles" ) and may not even be allowed gloves. With a back mounted pony, it's easier for me to stay off the coral.
WORKING WITH A BUDDY
From my point of view, the purpose of the pony is predominantly to allow ME to return to the surface. However, if either I or my buddy run out of air, we would abort the dive and return to the surface with one of us using the octopus attached to the pony. We would be in contact, using the same method to share air that many divers have already been taught in their open water classes. I didn't have to learn a new method for using my backup regulator or for sharing air. Importantly, there was also nothing new for me to teach my "buddy of the day."
HANDING OFF THE PONY BOTTLE
I can imagine circumstances where I'd want to hand off my pony bottle to someone else, but have decided to wait on adding that capability. In the future, I could get a pony bracket with an underwater quick-release such as the Quickdraw, and could have clips on the pony (like a stage bottle), so that I could attach it to someone else's BC. For now, my setup still improves safety over not having a pony bottle.
LEARNING CURVE
There is very little new that I had to learn to use my pony bottle. By mounting the pony on my back with my octopus coming from the pony -- my backup regulator remains in a familiar location for using or sharing.
NEW LEARNING: how to connect and disconnect my pony bottle bracket. It's similar to connecting a BC to a main tank.
BEFORE EACH DIVE: remember to turn on the valve on my pony, check the attached mini submersible pressure gauge (SPG). I also take some test breaths from the octopus attached to my pony bottle, but I normally test breath my octopus before each dive anyway.
AFTER EACH DIVE: verify the quantity of air remaining in case there has been leakage during the dive and remember to turn off the pony valve.
IN THE FUTURE
I may add a 2nd stage held around my neck with surgical tubing as some tech. divers do. That way, I'd have two regulators from my main tank, plus the pony+octopus.
It would be nice to have an SPG upfront and some day I may get one on a hose rather than a mini SPG. The mini's are harder to read, but a hose is something additional to manage, decreases streamlining slightly, and adds something else that could become entangled.
I hope this was useful to someone (Caribbean recreational divers?),
Phil