Why sidemount diving

Beware of any instructor who accepts you straight into cave course without insisting that you have technical-level foundational skills training on it first. Even the best divers cannot master a new configuration and a new environment at the same time. Details of both will be lost and the diver will be weaker for it.

Take your training stepwise and gain experience at each level, starting with fundamental skills in your configuration of choice. Tiny people will generally be more comfortable cave diving in sidemount. The main reason is more fundamental — short people will have difficulty looking up and forward using backmounted doubles because the manifold and tank position prevents it. In cave diving this is a safety and conservation issue — divers who cannot comfortably maintain at least peripheral vision of their team and the cave ceiling will have impaired environmental and situational awareness, and inherently will be less safe.

Divers who are already experienced with backmounted doubles may choose to enroll in cave training using their familiar equipment configuration. This includes divers who have experience in wrecks and those who have taken technical diving courses. There is no need to reinvent the wheel here. Divers who own their own gear and are comfortable in it are often happier simply focusing on learning to dive in the cave as opposed to increasing their task loading with new gear.

Sidemount does have some advantages in comparison with backmount, including the ease of moving tanks to the water. Divers using a sidemount configuration can easily view and access their tank valves and first stages, which streamlines the process of assessing and solving problems. And of course, sidemount is truly redundant, meaning that there is no single failure that can cause a total gas loss.

However, keep in mind that diving without a manifold means that in the event of a regulator failure, the sidemounter loses access to half his breathing gas. Backmount is by far a simpler configuration for the beginning doubles diver.

In sidemount there are more methods of solving problems and equipment failures, and to be proficient in sidemount the student must learn them. For this reason, sidemount fundamentals courses can, and should, take longer than backmount fundamentals courses.

From a safety standpoint, while there are a few vanishingly rare failures that can cause a total gas loss in backmount, the configuration has the advantage that the loss of a regulator does not mean that the diver loses access to half his breathing gas.

It is possible to breathe from both tanks with either one of the regulators, or shut down the isolator valve and save half the breathing gas if one tank is hemorrhaging. In either configuration, the diver still has his buddy as a source of emergency gas and gear. No one should be solo diving as a new cave diver. Keep in mind that you can still dive with friends who use a different configuration from you.

A proper, modern cave course should review both equipment configurations and prepare divers to gear match, gas match, air share, and dive with divers in a different configuration. Safe cave divers need a basic understanding of how both configurations work, even if they only dive one. The concept states that backmount is the preferable equipment configuration for all dives except those requiring a sidemount configuration — in other words, very tight caves.

I disagree with this idea because I feel that a diver should be intimately familiar with his equipment in advanced cave environments. This requires time in the water and years of familiarity to do correctly — not a short series of warm up dives.

If your goal in cave diving is to enter extremely tight caves one day, then I would suggest starting in sidemount from the very beginning, to maximize your in-water time with the equipment. Divers should still log hundreds, if not thousands, of cave dives and enroll in advanced sidemount training before entering extremely tight caves.

Most people who take up sidemount cave diving use it in big open places that a backmount configuration can also fit into. Very few recreationally accessible caves truly require sidemount configuration. In fact, there are definitely places where it is easier to fit with backmounted tanks such as narrow canyons. Backmounters go into very tight caves as well — they just remove their doubles to fit.

This requires advanced cave training in backmount but guess what… sidemounters should also take advanced cave training if they want to remove tanks to fit into places. I would count it as a disadvantage of sidemount that the configuration enables divers to enter tight places before they are ready or trained to do so.

Choose sidemount for its logistics and comfort, if they appeal to you, but save tight caves for your advanced cave diving career. Backmounters call sidemounters trendy, and sidemounters call backmounters antiquated.

All valid questions. Both from an instructional and a simply personal point of view I look at both configurations as tools that have different applications and come into their own at different times. This brings us back to the questions above. In North Bali, most diving is either from the shore or from small fishing boats. While we are lucky to have our own fiberglass boat at Two Fish Tech, not every dive centre has a boat. Many of the other dive centers in Amed use jukungs, small local fishing boats.

Jukungs and twinsets? Not a great match, especially when it comes to re-entering the boat after a deco dive via short ladders. In sidemount equipment? Easy — you simply get off the boat with your harness, mask, fins and accessories and clip on the tanks in the water. After the dive, they are easily unclipped and handed to the boatmen. Whilst handed valves are great for sidemount diving, you can just as easily rig up two run-of-the-mill DIN tanks.

This makes technical diving possible in areas where twinsets are hard to find or rent. Twinsets have been popular with technical divers for many years for a bunch of reasons. They allow access to all of your gas via one single regulator — handy if regulator number two has a problem. They also provide a stable platform. When diving in a current, especially an up or down current, that can make all the difference between a manageable and an extremely stressful dive. Remember, many technical diving situations require multi-tasking, so being comfortable in your equipment is paramount.