Scuba Leeds Blog - Hollis Katana Review

Why Hollis' SMS Katana

I have been wanting to write something about the Hollis SMS Katana for a while. Sidemounts is one of our favourite subjects at the dive centre. When it hit the recreational training arena in 2010 it was labelled as a "fad" and wouldn't last. Well we are coming to the end of 2016 and its still here and still growing. True its not as popular as twinsets, yet. But it has definitely gained traction. I started diving sidemounts in early 2010, not that long ago compared to many cave divers, but still pretty early on in recreational terms. My first system was a Farr World Explorer harness. This was literally a harness and I dived it with two Ali 7ltrs slung on my sides. This was not pretty, but it worked. It was a far cry from what I would learn in the summer of 2010 when I completed my first sidemount course with a friend of mine who had just returned to the UK after 3 months training with Steve Bogaert in Mexico.

First the SMS 100

Steve Bogaerts had been diving using a camel pack (drinking pack) for buoyancy with a wetsuit and harness, this wasn't something that I was keen on. That month the Hollis SMS 100 was launched and I was straight in there, keen to get as much diving on the system as possible. The SMS 100 is a great multi-use system, that can be used for singles, twinsets and sidemounts. Its was using the SMS100 that I honed the basics of my sidemounting. Within a month of my course, I had completed 50 dives on it ( a Red Sea Liveaboard helped boost the numbers) I was keen to really get my teeth into this more. I saw the potential of sidemount for recreational diving and there was no one in Yorkshire teaching it.... AND I LOVED IT. Skip forward in time a little and the dive industry started to catch up, with the release of the a number of sidemount systems from a bunch of manufacturers with a varying degree of finesse in their products. I bought everything, I wanted to know what each system did and the only way to find out was to buy it and dive it. I bought a Diamond, an X-Deep, a Custom Divers and even dived a bunch more including the OMS and Dive Rite systems. Honestly saying one sidemount system is like another can not be further from the truth. I have tried most of the options that are out there and have taught a lot of sidemount divers at both recreational and a number have gone on to technical sidemount with me as well.

The Razor Sidemount System

In June 2011 I was in Malta diving with an old friend of mine (obviously I mean we had been friends a long time!), Alan Whitehead. I was completing my Tec Deep Instructor with him and while I was there he showed me the brand new Razor Harness and Bat Wing system that he had just been trained to teach by Steve Bogaerts. Less than 5 minutes later we setting one up for me! In all honesty its a pain in the arse to setup the Razor, but when its right, its great. I then spent a couple of weeks in Malta completing both recreational and technical dives with Alan in the Razor. What I really loved about the Razor was its sole use for Sidemounts. After having the SMS 100 and bringing them into the school in later 2010, I was fortunate to have another good friend of mine, Rich Howes, as the sales rep for Hollis at the time. Rich turned up one day with the shiny new SMS 50, which was the first dedicated Sidemount system that Hollis had produced and it was a great hit. We switched the school systems from SMS 100 to the SMS 50 and continued to train divers using these systems. Mark Cato was my first PADI Tec Sidemount & PAD Tec 40 student to complete the course using the SMS 50. He has become a very skilled sidemount diver, having completed a Sidemount Try Dive with me on his 10th dive, he was hooked.

The Hollis Katana Sidemount System

Bringing you up to the Hollis SMS Katana system being added to the school fleet. So why did we decide this was the right sidemount system for Scuba Leeds. Well for a number of reasons. The Hollis SMS Katana is a dedicated sidemount only system, which means its been designed with only this in mind. The Katana wing is designed to wrap around the body like many of the other systems, however there are a number of features of the wing that allow this to be done with greater adjustment to the divers needs. The dump valve placement for the wing can be in 3 places, left or right kidney or at the base of the neck. The Hollis SMS Katana harness comes in a basic H style, not my preferred method of harness for sidemounts. Simply unthreading the webbing and moving the harness mount to the base of the spine tightens the entire harness making it more secure for Technical Sidemount. With the change to the harness in this way, the chest strap can be removed as the shoulders should now not move or slip.

The Bungees

We have also changed the bungee system from independent bungees to single bungee, which is my personal preference. A utility pocket has be fitted to the base of the harness with a back up bungee and a number of other sidemount accessories. A trilobite line cutter has been fitted to the waist strap of the harness which is accessible with both hands. One major benefit the Hollis SMS Katana has over a number of other systems is the intergrated weight system. This is the velcro padded section in the centre of the spine. This opens up and receives weights. The great thing is that this can be adjusted up or down the spine as the diver requires. Rather than having to thread weights onto the system or having a fixed pocket to put weights into. The Hollis Katana diver can truly adjust the weight position up and down easily when the are adjusting weights. Then once the weight piece is in place it doesn't move, but the weights can be removed at the end of the dive. Result.


I really like what they have done with the Hollis SMS Katana, its a superb system. Sidemount diving systems have progressed a lot and this ticks all the boxes for me. We have our first course of Sidemount Divers using these systems in a couple of weeks time. We will get loads of pics and review the system in more detail then.

Alex Varnals PADI Tec Sidemount & Techincal IT

Dive gear review


Alex Varnals

Alex Varnals

Hey Scott, I have never dived this wing with steel 80’s, but I have used this wing a lot. I would think this wing would have more than enough lift to manage steel 80’s (which I am assuming are the same as 232 bar 10ltr steels here in the UK). The wing does have a good amount of lift and should manage this easily in a wetsuit :)

Alex Varnals
Scuba Leeds

scott a young

scott a young

can this unit be used with steel 80’s hp and a wetsuit

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