Hollis Katana 2: Why It Became My Sidemount BCD

Disclosure: This is an independent account of equipment I use or have used. I work in the diving industry and sell some of the brands or products mentioned, but I am not paid or sponsored to promote them and none of the equipment discussed here was supplied to me free. My preferences are personal conclusions from use, not universal buying advice.

Safety note: Equipment articles cannot replace formal scuba or technical-diving training, a manufacturer manual, a gas plan or a dive plan. Configuration choices must make sense for the diver, environment, team and training involved.

A long-term, experience-led look at why the lime-green Hollis Katana 2 became my preferred sidemount BCD, what its design changes underwater and where it does not suit every diver.

My personal reasons for choosing the Katana 2. Sidemount is where most of my current diving life happens, so the details that once felt optional have become very obvious after repeated use.

What I notice in sidemount

I previously taught and dived extensively with other sidemount systems, including the XDeep Stealth 2.0. What attracted me to the Katana 2 was the feeling of a modern interpretation: valve access, adjustment, weight integration and a back section that feels ready for demanding environments.

Mine arrived remarkably close to dive-ready, with the bungees organised in a way that required sizing rather than redesign. It leaves room for accessories I do not currently need, which is important because modularity should not force clutter.

And yes, the lime-green version matters to me. Good equipment can also be something you enjoy looking at.

The practical point

For me, the value of the system is not that sidemount is automatically better. It is that this configuration solves the problems I currently care about with very little wasted hardware.

Why the Katana 2 won me over

I had already spent years using and teaching with the XDEEP Stealth 2.0, which I still consider an excellent system. The Katana 2 appealed because it felt like a more modern interpretation of what I wanted: valve/dump placement that made sense to me, a reinforced rear area, a very usable weight system, fast adjustment and—importantly—factory bungees that were already where they needed to be. I sized the harness carefully, but I did not feel I had to redesign the BCD after opening the box.

Hollis documents the Katana 2 family around a configurable H/Y harness, integrated weight capacity and a roughly 40 lb lift class. Those specifications provide context; what keeps it in my personal system is how naturally it disappears around me once adjusted. And yes, lime green matters to me.

Why sidemount changes the equipment question

Sidemount is not simply backmount with the cylinders moved to the sides. Cylinder position, hose routing, regulator orientation, attachment points, buoyancy distribution and access all interact. That is why small details become important: the length and position of a bungee, the angle of a first stage, the position of a lower clip, whether an S80 has started to become positive, and whether an accessory can be removed for a particular dive.

Most of my diving today is sidemount. I may use one aluminium S80 for a recreational dive and two for more demanding or technical dives. One of the practical benefits for me is logistics: cylinders can often be placed in the water before I kit up, so I am not carrying the complete mass of the system across land. Underwater the cylinders become part of a very clean, balanced configuration.

Minimal does not mean stripped of safety

Minimalism only works when the remaining equipment still covers the actual problems. My two-cylinder setup gives me independent gas supplies. My current regulators keep a mechanical pressure indication even though wireless transmitters are my primary way of seeing pressure. A drysuit may provide an independent buoyancy source on a technical sidemount dive where the wing has a single bladder. Those are deliberate layers; they are not decorative redundancy.

The same thinking explains why I do not automatically fit every possible clip or accessory. If I know I will carry a cylinder out of the water, a neck clip can be useful because I can transfer the load to a D-ring rather than the bungee. If I will leave the cylinder at the water’s edge, that same clip may add no useful capability. The correct answer depends on the dive.

Configuration has to be lived in

A sidemount system can look perfect on a floor and be irritating in the water. The test is whether I can reach valves, switch regulators naturally, read or recover pressure information, donate gas, control buoyancy and propulsion, and keep the system quiet against my body. That is why I value the details of my digital sidemount gas-management configuration: information moved to the wrist, while mechanical backups stay small and protected at the first stages.

What I check before calling a sidemount configuration finished

I want valve access, stable cylinders through the gas range, repeatable regulator switches, uncluttered donation, usable inflators and a body position that does not require constant correction. Then I deliberately move, roll, reach and breathe from each side. A configuration is finished only when it still works while I am doing the dive rather than posing for a photograph.

Current manufacturer context

Hollis currently documents the Katana 2 Dual with approximately 40 lb of lift, 20 lb of integrated weight capacity and a harness that can be configured in H or Y form. The family includes single- and dual-bladder variants. Those numbers help describe the platform; they do not determine whether the harness is correctly adjusted for an individual diver.

Hollis — Katana 2 Dual product information