Think of technical diving and a picture of a diver in black carrying a heavy twinset comes to mind – pretty similar to the picture here. But think of cave diving and that picture often changes to a sidemount diver.

Both kinds of diving simply simply require different equipment. So far, so good, but what do you choose when you’re looking to get into technical diving? We’ve put together a bit of advice.

where to start with twinset or sidemount

Naturally, most beginner-level technical divers aren’t sure yet where their technical diving career is going to take them – whether it is down deep walls or into the more restricted spaces of caves and wrecks. Faced with a decision over which configuration to choose for your training, a number of factors come into play, including:

• Water access: will you be diving from large boats or entering the water from the shore?
• How about equipment availability: are you planning on getting your own twinset or will you depend on rental tanks?
• Physical limitations: how much weight can you carry at once (on land more so than in the water)?
• Learning experience: as a technical diver, wouldn’t it be good to have a grounding in both twinset and sidemount diving? Of course, with time you will develop a preference for one or the other configuration, but understanding both and their advantages and disadvantages will help make you a more rounded techie.

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.

Advantages and disadvantages

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.

Next, let’s take a look at equipment availability. 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.

2:0 Sidemount! Hmm, let’s not rush to judgement here.

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.

Looking ahead, you may not always want to restrict yourself to 45 meters and a single deco tank or even 50 / 60 meters and two deco tanks. Greater depths require more gas and once you start carrying more than four sidemount tanks, things get a bit tight around the middle. Effectively, you would be losing out on the comfort of sidemount, one of this configuration’s biggest advantages.

2:2 We have a draw!

Personal preference

Hand on heart and conditions notwithstanding, I love sidemount diving. I enjoy the feeling of not having anything on my back and I do like the flexibility and modularity of the setup: the fact that you can decide to leave a tank behind if you’re planning to enter a smaller space on a wreck, for example.

Sidemount equipment also travels well. BCDs tend to be reasonably compact and light-weight, and rigging is not bulky either, perfect for the intrepid tech diver. So, do I ever dive in a twinset still? Yes, because with a well-adjusted harness and good trim it is just as comfortable to ‘hang off’ a wing. A bit like skydiving, maybe.

Knowing it all…

… AKA diving in mixed teams or being a well-rounded diver. Whatever your preferred configuration, it’s a good idea to know a little more about other options and the setup of your team mates:

• It will allow you to help them more quickly and efficiently if there is a problem.
• It gives you a choice for your own dives. Rather than having to stick to one configuration, you can simply pick which ever suits the conditions best. And what’s not to like about that.

What do the training agencies say?

At Two Fish Tech, we teach both TDI and PADI courses. Both agencies allow instructors and students to choose their configuration for their technical training. This does mean that a number of underwater skills will be taught slightly differently, but fundamentally the training will be the same.

In order to get to know both configurations, you don’t have to complete your courses twice. One option would be to choose your preferred configuration initially and then add a configuration course to cover the other one. For example, if you have completed decompression dive training in a twinset, add a sidemount course to find out what that feels like.

Alternatively, if most of your training has been in sidemount, then completing a 2 day Intro to Tech makes a lot of sense.

Is there a one-size-fits-all answer? No, there are plenty of considerations instead. At the end of the day, most divers committed to technical diving tend to be curious enough to at least have a go at both configurations. And I haven’t even started talking about rebreathers yet….