Sidemount Diving, Cozumel Trip, Do You?

[MichaelMc]

Typically the dive boat, which is a tiny outboard skiff with 6 divers, pulls up to an approximation of the dive site and starts drifting.

Thanks for the detailed writeup. I'm not sure all the parts are as complex as you describe. Rigging hardware on a new set of tanks each day seems no harder than rigging a BC on two tanks each day.

Plus, if the trip is short, sidemount divers can wear their rig with no tanks for the ride out. They can descend with bottles clipped but not bungeed. Front clip both, roll, check your own valves, descend. Sidemount divers can do their own checks, its sidemount 101, particularly if experienced as a solo diver. Watch the other five divers do their backrolls from 10' down. Now, it needs to not be your first sidemount dive....

Plus you describe handing up BCs and weights; BCs are bulkier than tanks. Sidemount divers should know to clean up their hoses and tanks on ascent and safety stop, not while dithering on the surface. Someday I'll get to Coz and see.

I'm not sure why you keep bringing in manifolded doubles as a comparison. Single tanks are much more maneuverable and individually half the weight on land, which you know.

what's the point of having two tanks?

Redundancy. Scuba with strangers 101, well discussed on the board.

 

[halocline]

Redundancy. Scuba with strangers 101, well discussed on the board.

We could down a real rabbit hole with this, so I'll make this comment and then disappear. Every freaking day, dozens of divers, some days hundreds, go on dives in Cozumel. This has been going on for, oh I don't know, 30 years lets say. Practically every one of those thousands and thousands and thousands of dives was made on a single tank with no redundant air source. How did they ever survive?

And this 'discussed well on the board' bit as some sort of validation is all very nice, but it doesn't really jibe with the real world, you know, the one where recreational divers use single tanks and live to tell the tale. Not the internet version where 'strangers' will cause your death if you dive with them without a bailout bottle.

Ok, sorry for the condescending rant, it's nothing personal. My apologies.

 

[Andrew Dawson]

Yeah, the preference is two tanks for redundancy...I have had awesome buddies who became friends and helped me be a better dive....and buddies who, when asked how much gas they have left in their tank, did not have enough gas to surface with from 70fsw....and had to use my pony to get the surface with air. They had no idea of conserving gas to live on.

I do solo dive often...and love it. Going to BM for this trip sounds easier than SM...with the type of boats, the infrastructure, they type of diving [non-cave], etc.

tho...BM is inelegant and less safe than SM, IMHO. Now, I do not have all stats in my hands to fully back up the claim of SM being safer than BM...but...logically, the more gas options you have underwater, the better, right? I do have nothing against BM nor will I say anyone is wrong for doing it. For me, it is like flying an airplane that has a parachute built onto the plane [they make these]....and having to switch to one that does not have one. Sure, both methods are acceptable...I have just gotten used to one...and mentally, it is a switch to reduce my amount of immediately available gas options that has me a little uncomfortable.

I am still slightly on the fence here...but...I believe I will go with one of these options in order of preference:

-BM, single tank rig...rented BCD but my own regs.
-SM, single tank rig with 2 2nd stages [however, I have never done this before...and not in warm water, tho, I could test this easily around here in the PNW...just get in with one tank on my SM kit. For this, I would use chokers on land...heck maybe underwater, too...and then maybe do loop bungees as that is what I am familiar with.

The BM single tank rig will be much easier to deal with, that is assured, all around, in this case, IMHO.

 

[MichaelMc]

Ok, sorry for the condescending rant, it's nothing personal. My apologies.

No worries. My 'It doesn't seem that complex' post had a bit of sarcastic until I trimmed it back.

To each their own.

 

[SlugLife]

@halocline This wasn't an argument, but you seem to be reading this topic as if it was an argument. Obviously, there may be some downsides to SM & of course beware you don't want to be the super-slow-SM diver that holds everyone up (not all SM divers are that).

@Andrew Dawson

If BM is simpler for this vacation, then a "vacation" from SM might not be a terrible idea. If SM makes your vacation complicated, then I'd say leave it behind for a week.

However, if you really want to SM, go for it! Have fun, it's YOUR vacation. If you want to SM because ... you enjoy it, the redundancy, etc, then do SM. You're not hurting anyone else. You might get a few looks, but whatever. People give me looks when I have a pony-bottle, as almost nobody does that locally.

I recently skipped SM on a couple dives, because I was super-new to SM, very slow, and had limited time for those dives because I was with friends and we were treasure-hunting. I didn't want SM or my slowness to get in the way. However, after some more practice, and refining my kit, the next treasure-dive I decided to roll with my SM kit. Yes, I was a little slower than my friends getting in the water but not terrible. In time I should be as fast (or faster) than them.

 

[Diving Dubai]

Please don't take any offense at this, but maybe you are a superhuman who can rig a two tank sidemount system faster than single tank divers can back roll and rinse their masks, but that is NOT the norm. I know this because I do both things frequently. You can't really expect a typical person to be able to do this, at all.

It would be extremely cumbersome to fully rig a SM system in the Cozumel skiff where there is barely enough room for the 6 divers in single tanks, and then try to back roll off the boat in SM. And it would be impossible to climb the ladder with your SM tanks on. So in this specific scenario the option is to rig don/doff tanks in the water, and in my earlier post, I explained in detail why that is impractical on Coz reefs.

I take zero offense because there was none intended and its part of the discussion.

I'm certainly not superhuman, in my mid 50's and generally prefer the easiest solution.

My preferred local diving, uses a small chase boat for for dropping and picking up divers. you sit on the gunwales with the gear piled on the deck. When you put your fins on the person opposite needs to move their feet. Spacious it's not.

My diving group are all similar aged diving curmudgeons and we collectively have a PHD in grumpiness and intolerance for faffing. If a SM rig caused any delays or inconveniences, you'd be told very directly.

While I've never been to Coz, my vacation diving is generally to Indonesia. Similar set up to Coz with boat sizes with the main difference (on the trips we take) we're deliberately dropping into significant currents, so there's no leeway for messing with kit on the surface.

The points you made are valid, and this is why (I thought) I'd been clear to the OP and others, that the SM rig needs to be configured and optimised for boat diving.

This is why I use the ring bungee method, where the tanks have a mechanical connection to the chest webbing allowing you to be able to climb the ladder with both tanks. Although I'm more than happy to detach the tanks in the water and hand them up if the conditions allow.

Now if someone turned up with a rig configured for shore diving needing to clip off a tanks at the side of the boat prior to jumping, then I'd fully concur with your POV. I'd have no time for them either.

[EDIT] The problem with SM, is so many "practitioners" think that one config does all. It doesn't. In BM singles swapping from Steels to Al all I need to do is adjust the camband(s) and maybe add/subtract some lead. SM requires a bit more adjustment [/EDIT]

And to be clear I'm not a SM evangelist, far from it. I'm happy enough guiding divers around a shallow reef in my jacket and a single AL 80, or in my wing with a single large steel and Al 40 slung to the side.

But for travel vacation rec diving my SM is perfect.

Trust me if it wasn't or caused even the slightest inconvenience to others, my wife would let me know in NO uncertain terms!!

 

[ggunn]

We could down a real rabbit hole with this, so I'll make this comment and then disappear. Every freaking day, dozens of divers, some days hundreds, go on dives in Cozumel. This has been going on for, oh I don't know, 30 years lets say. Practically every one of those thousands and thousands and thousands of dives was made on a single tank with no redundant air source. How did they ever survive?

I have been diving Cozumel for a couple of weeks or more every year since 1994 (except 2020), and in all that time I can remember seeing a diver dive with a redundant air supply exactly twice.

 

[halocline]

No worries. My 'It doesn't seem that complex' post had a bit of sarcastic until I trimmed it back.

To each their own.

Thank you!

 

[Andrew Dawson]

BM reg has been built and tested!!

Kit is 90% there...just need a few items to arrive [yoke dust cover, yellow S600 face cover for the "octo" reg, pack all items]

I am genuinely excited about this...and after actually disassembling the SM regs, building the BM regs, it brought me back to my early days of scuba diving. I trusted the BM setup as-is I see the designers vision of having an uber reliable solution to folks wanting air underwater. No, it is not as good as redundant air supplies [SM, pony, etc]...but...it will work and we have the statistics to back it up...BM is acceptably safe for most diving...and for the recreational [albeit drift at times] diving in Cozumel with guided tours.

I totally thank everyone for their opinions, experiences, and knowledge shared on here!!

 

[ggunn]

...and for the recreational [albeit drift at times] diving in Cozumel with guided tours.

It is a rare dive around Cozumel that is NOT a drift dive. Have a great trip!