I want more bottom time so I’m trying to decide between sidemounts and twin tanks using a manifold on my back.
At the risk of sounding snarky, let me be clear. I have hundreds of dives under my (weight) belt. I’ve very comfortable under water, I frog kick, I’ve done technical diving and I’m certified in cavern and caves. In the latter, I dove with twin steels. In other words, I don’t need to hear “you just need more dives so you feel comfortable, then you won’t need multiple tanks.” O.K. off my soapbox.
From here on, my dives will be recreational and open water. In other words, no caves or technical wrecks. On an aluminum 80 I get 40 – 45 minutes at best. Either way I go it’s going to cost me money. Here are some pros and cons.
Twin Back Mounts On A Manifold
Pros: - I have experience with them.
-I can use my existing regulator.
Cons: - Need a backplate, wings, and a manifold.
- Heavy on my back.
Sidemounts
Pros: - Easier on the back
-Perhaps a little more flexible???
-Easier to maneuver on a small boat.
Cons: - Need certification
- Need sidemount BC, additional regulator, hoses etc.
Am I missing anything? For those that have done both, which do you prefer and why?
Thanks!
I love backmount diving. I miss my backmounted doubles, but after shoulder surgery, I can't reach my left valve in backmount, so sidemount it is.
I'm still assuming that you're local and will be diving at BH, so here's a couple of other thoughts for you:
Sidemount Cons:
1. Getting your gear on, while on the ledge, is a PITA. AL tanks don't like to sit nicely on the bottom and there's nowhere to lay them down until you can get them on. 5,137 open water students walking by while you gear up doesn't help either. Prepare to take a long time to get your gear on - you have to put your fins on before you put your tanks on, so placing tanks on the stairs isn't convenient. It pays to have a patient buddy who's willing to schlep them down to you one at a time.
2. On weekends in BH, it can be busy enough that you've got to maneuver your body into positions (vertical!) or roll over to make sure someone isn't dropping a class full of seahorses on you during your ascent. It is hard to look cool when you do that in SM, and frankly it's easier in BM.
3. Transitioning from wet to dry suits can be problematic for fit and function. It isn't impossible, but if you have to start adjusting fit of your harness, you might as well get a new wing and save yourself the hassle. I'm building a second SM rig so I don't have to.
4. You will take longer to get ready for the dive. If you're diving off a boat that may cause some consternation with your fellow travelers.
5. Trim and buoyancy may take you some time before you're comfortable. For me, it was a surprisingly long process.
These I don't see as a big issue:
1. Cost of wing - lightly in favor of BM, but not by much, as long as you compare purchasing a BP/W to SM.
2. Regs - unless you are planning to dive with one first stage on the left post? <shudder> - the only difference in cost is an extra spg or transmitter. If you've already got a din reg for BM, the cost is going to be fairly manageable.
3. Training - I don't think you necessarily need certification in SM - you can certainly train yourself, but good training will speed up the learning process. Sidemount.com hasn't been mentioned, but that might be a good place to start if you wanted to go that route. You pay somewhere between 2-300 for a year of videos, and I charge 600 for a weekend of pool/getting your gear fitted and 2 weekends of diving.
4. Experience - You'll find doing things like valve drills and S-drills much the same, so that should be a pretty easy transition. There's a few little things that are different, but it isn't going to feel too unusual I think.
Sidemount pros:
1. There's no rule that you have to dive 80s. You could get some 63s from Stella or invest in some lp50s or al40s. Staying within your NDL should get you two dives at BH in 80s though, so they would be cheaper if you're paying for fills.
2. You can also dive with one tank in SM (it's kind of fun to do!) - I wouldn't do that regularly, but I'm still doing tech dives... I can't think of reason that you couldn't regularly do that recreationally though. You lose redundancy, and the cool tech diver look though.
3. Knees! But you know that.
4. Once you've mastered your new gear/trim/buoyancy, you can get into positions in the water comfortably that you can't hold in backmount because your tanks want to roll you...
5. My air consumption is better in SM than it is in BM with a single tank. Maybe because I'm more streamlined, I'm not sure. . .
6. Even if the bovine excrement hits the rotating, oscillating blades, in some really bad way (like both your regs start to freeflow at the same time, at 130 feet, and you accidentally rack up a deco obligation before you start your ascent) you'll likely feel just fine as you ascend and do your deco stop. Feathering valves is easy.
I'm not sure what you mean by sidemount being more flexible, I can't comment there.
