The issues with sidemount are many.
First, the amount of gas in a single cylinder naturally limits your dive. Most liveaboards run on a schedule, and the guy making 2 hour bottom times messes with the schedule. Your response: I'll limit myself to an hour bottom time. Our response: We'll limit you to a single cylinder.
Second, walking around on the deck of a rocking dive boat with 2 poorly rigged cylinders is cause for great alarm, not only for the crew, but for the other customers getting banged by your cylinders (who then complain tot he crew. You can't believe how many really poorly trained and self trained "sidemount divers" there are out there. Your response: (with a bit of huff) I know how to rig my cylinders. Our response: Yes, in the middle of your BC/Backplate is fine.
Third, a giant stride from 6 feet with even properly rigged sidemount cylinders can me onerous. The jump gate and entry gate are wide enough for a diver, not wide enough for a diver with 2 cylinders hanging off their hips to get through without hanging up on everything, banging the bulkheads and handrails, chipping the paint, etc. Dive-aholic (Ron Neto) has successfully jumped off the Spree with 2 steel 104's, 2 40's and his scooter. Rob is an exceptional sidemount diver. Others, not so much. Your response: I'll just have the crew lower my cylinders to me when I'm in the water. Our response: Say what? Your response: I'll just take my cylinders off and hand them up to the crew. Our response: Say What? Your response: If I chip a little paint, no biggie, you can patch it. Our response. Here's a single 80. Go have fun.
Fourth, even if I would lower your cylinders to you, or haul them back up, we want you in your scuba gear working and ready to use when you jump off the boat, and when you get back on. We want your regulator in your mouth when you giant stride off, and as you come up the ladder so we know it's working and your air is on. We want you jumping off and getting back on fully rigged so if the current is blowing like a hooker at a convention, you grab the granny line and head off towards the dive site. We don't want you flopping and twitching at the surface trying to get clipped in. The other passengers don't want to wait just 5 minutes while you get yourself situated. Your response: Well, I've paid just as much as them to come on the trip. Our response: Yes, but you're using twice the resources.
Last, I dive a pony for redundancy, just like you dive sidemount. Exactly like you dive sidemount. My pony is small and unobtrusive, rigged to my main cylinder, in fact, I use my doubles backmount setup to dive, with my left post reg with long hose on my main cylinder, and my right post reg with bungeed short hose on my pony. Your response: I like sidemount and I'm trained. Our response: Here's a pony for rent. Would you like a solo class too?
I'll stop short of calling sidemount a fad, but what I will say is that sidemount is a great tool for slipping through cave restrictions where it isn't proper to use backmount gear. There are no restricted caves where liveaboards tend to take their passengers. When you find a restricted swim-through in a coral reef, we really don't want you bulldozing your way through it anyway. If you are desperate to dive sidemount, Doppler is chartered for a trip on the Spree in August and another in September where he will be giving tips on sidemount rigging. It is an Advanced Nitrox and Deco Procedures trip, and doubles are welcome, because we're set up for it, and welcome it. Same price as a regular trip, but you get to dive to the limits of your certification. Recreational sidemount divers are welcome, because everyone knows what we are getting into.
Yes, we know we are limiting our clientele by not allowing sidemount on recreational dive trips. It's worth it.
