Mark Lewis


From Latin ūrīnāns, plural ūrīnantēs, meaning ‘Those who dive’.

Since learning to dive in 2012, I have posted on social media my more memorable dives and more recently, publishing trip reports on our club’s website. That got me thinking. Reenergising concepts and data from an older website and porting some of that dive related content content here, I want to publish a “blog of logs” here. That is, some of the more interesting ones.

Living in the UK, most of my dives are around the British coastline and tending to prefer tin to coral and critters, my preference is shipwreck diving and more importantly the history behind the wreck. Many ask what is my favourite shipwreck and that is a hard question to answer as all have special memories. Ask that question differently, “What are your most memorable dive sites?” and that will spawn a long list.

Why Ūrīnantēs? In Classical Latin, the verb ūrīnārī meant “to dive into water”, ūrīnātor was “a diver” and ūrīnantēs “those who dive”. Latin ūrīnātor (“diver”), from ūrīnārī + -tor (suffix forming a (masculine) agent noun). Ūrīnārī is the present active infinitive of ūrīnor (“to plunge under water, dive”). So welcome Ūrīnātors, one and all!

Mark Lewis

I first qualified as a PADI Open Water diver whilst on holiday on Sivota, Greece in 2012. I remember it well as it was the year of the London Olympics. It was not my first time of diving, that experience came in in the mid 1980’s on a lads holiday in Cyprus. Someone came up with a novel idea that we could stay underwater while the topless girls above swam by overhead!

My next baptism was in the late 80’s when my now wife and I had our first holiday together in Eilat, Israel. A vivid memory of a Red Sea shore dive with the plethora of tropical fish. But it was not for her and hence that was that until 2010 when our then 13 year old daughter wanted to try diving while we were in Bermuda. We had been to the local BSAC club beforehand and they said she had to be 14 or older to dive. Today I would call our Bermudian experience a try dive and with all skills practised, it was a giant stride off on a big Gin Palace.

But here’s the twist. As a father, I felt total responsibility for not just myself, but my daughter too. I was told to step into the water and swim out to the buoy. I did that and while holding on, found that the waves were lapping over my head and I was struggling to keep afloat. There was no-one else around me! Yup, there was no instructor! Whether I was overweighted or not, one thought passed immediately through my mind and that was, if anything was to happen to my daughter, I could not help and at that point I waved my arms and swam back to the boat before she got in.

Two years later and we were in Sivota to the beckon call of “Dad, can we try scuba diving again?”

PADI Open Water Diver

Long story short and after a pool try dive, we both enrolled on the PADI Open Water course and within a days, we were qualified. I remember vividly that I had so many questions, but a simple accolade from the instructor that my daughter and I can now dive anywhere in the world to 18 metres in depth. With just four training dives and a theory test passed, we could hire some kit and dive together anywhere the world, even though our maximum depth at that time was 12 metres. Something just didn’t seem right.

Back home to Blighty and I we talked to our local BSAC club again and an affiliated PADI agency called DiverSity about training. You see, I was doing a lot of motorsport racing at that time and with the 2012 season over, I thought diving could be a new hobby and pass time for the winter months. Hooking up with the guys from DiverSity and a trip to Simply Scuba in Faversham to buy our own fins, mask, snorkel and wet suit, my 5th dive was at Wraysbury.

Sivota 2012 - PADI Open Water Course.

Fuckerdy fuck it was cold! Fuckerdy fuck it was green! And I could see fuckerdy fuck all! But with two dives that day and two more a fortnight later at NDAC, I was beginning to like this new hobby. So with the DiverSity guys, I went on to complete the five speciality courses of Drysuit (NDAC), Peak Performance Buoyancy (NDAC), Wreck (Stoney Cove), Deep (Stoney Cove) and Navigation (Wraysbury). By this time I had purchased my drysuit, BCD, cylinder and regulators and with a little alchemy on 2nd June 2013, I was now qualified as a ‘Master Scuba Diver’. A shitty title, but huzzah!

My motivation now was simply to get some diving in and I joined the Divestyle Pirate Club. Juggling my 2013 race calendar, my first salty UK sea dive was planned to be a weekend in Porthkerris with the club. But I was nervous and after a little Googling, I was introduced to a chap who took me for a dive around Swanage Pier and then the Valentine Tanks as a pre-weekend check dive and weight check. Oh and what a palava that was including loss of buoyancy, uncontrolled ascents and loss of buddy! I’ll leave it there! Suffice to say and after some more quarry work, I was ready for Porthkerris.

The Fascination With Wrecks

And that’s when it all started, at Porthkerris that sunny June weekend. My first shipwreck dive was the Spyridion Vagliano [+1890] on the Manacles. I remember skipper Dave telling the tale of the captain making it to shore and doing a runner. That in contrast to newspaper archives of the era saying he drowned. Our fourth and last dive was on the popular SS Mohegan [+1898] again with Dave’s tales but a more human factor that many of the dead are buried in a mass grave at St Keverne.

Then What?

Pretty much a fortnight after Porthkerris, it was a family holiday to our apartment in Cape Verde where it was back to the blue and warm waters. Back to the UK for some more wreck diving from Swanage and then to Dubai for a crazy dive in the Shopping Mall aquarium with my daugher. Back to the UK and more Swanage diving, then a week on a Red Sea liveaboard, back to Cape Verde and in February 2014, sidemount!

You see, there was this fashionable new thing called “sidemount” and everyone was talking about it. The plan with the Pirate Club was a trip to Scapa Flow and talk of something called redundancy and that I needed sidemount. And like a lemming, I popped across to Malta to our friends at TechWise for a sidemount course. I remember is well, my O’Three drysuit, a Hollis SMS-50 and two steel Faber cylinders. Crikey!

Tell Us About Sidemount

It’s great! Hmmmm, let me rephrase that. It’s OK. The course in Malta was brilliant. I didn’t like the SMS-50 and I was told the only other wing was the Razor as used in Mexican cave diving. But I am not a Mexican cave diver! Anyway I passed and back home to the UK with a silly question of “How the hell do I don and doff cylinders with 5mm gloves”? So it was off to Vobster for a UK derivative of the IANTD sidemount course, a la “Self Reliant”. Sidemount was seeming a growing fashion and after being showed two options of sidemount wings, one the Hollis SMS-50 again and the Dive Rite Nomad. I completed this hybrid sidemount / self reliant course which told me that I simply need bigger bolt snaps for cold water and more so, I felt more comfortable with two cylinders.

There was no X-Deep or Apeks or Scuba Pro rigs at the time. There was talk of a SMS-75 and a SMS-100, the latter some sort of ‘catch all’ device for backmount and sidemount diving. I opted for the Razor and met for the first time Oliver Van-Overbeek, the UK distributor for the product.
Zenoba Starboard Prop
PADI Tec45 2015 - Sidemount on the Zenoba. Starboard Propeller.

Oli took me through the setup process and some educational dives, a crossover if you like. There were three of us who had purchased Razor’s from him around the same time and the four of us spent quite a lot of time together at Vobster with various equipment failure scenarios and pretty much from then onwards, it was sidemount for me. I completed my PADI Tec40 on sidemount in Malta with TechWise and then my PADI Tec45 in Cyprus on the MS Zenobia [+1980] with Alpha Divers.

But here’s the rub. During this time and other than a trip to Bali and my Tech45 course, each and every dive I made on sidemount was from the shore. Sidemount was just too clunky for UK boat diving and with two 14KG cylinders hanging from your gonads on a rocky boat in a drysuit just doesn’t cut the mustard. Sidemount was not for me and in March 2016 I ditched the sidemount rig and ventured onto a twinset.
Zenobia Kissing Lorries
PADI Tec45 2015 - Sidemount on the Zenoba. Kissing Lorries.

Twinset Diving

It was early 2016 when I met a chap called James Sanderson. Around that time I was debating with the idea of dumping the sidemount system and James happened to be advertising himself as a GUE Fundies instructor and coincidently, was the UK salesman for Apeks.
Vobster Quay 2021 - Twinset Diving For Photograher.
It didn’t take too long before James and I has planned a date at Vobster for a day of backplate fettling and rig setup.

Later that year in May, a few of us went to Malta for a week. Oli was there under his RAID UK and Malta guise and I caught up with him for a little skills coaching before the week of holiday diving. I remember feeling very comfortable in a twinset rig, more so than any single cylinder or sidemount setup. Everything seemed quite perfect with excellent trim and with the GUI/DIR configuration, all kit was neat, tidy and in the correct place. Then just two months later I was back with Oli in Malta, having completed my IANTD ART course and now as ‘rent a buddy’ for a week, it was a week of coaching with some cracking technical diving on the Um El Faroud, MV Karwela and the Imperial Eagle. All this as planning and preparation for our first trip to Chuuk Lagoon.

Bubble Free World

Fast forward to June 2016 and having discussions about Normoxic Trimix certifications, the baby was thrown out with the bathwater and I took the plunge into the bubble free world of CCRs. Having done a try dive at Vobster, my weapon of choice was the VMS Redbare. Now, there’s a whole new schema of thoughts. Many say it’s like learning to dive all over again. I wouldn’t say that, but a whole new way of thinking.

So what’s the appeal of a CCR and what makes it so clever?

In simple terms it’s a gas blending machine on your back, providing the most optimal Nitrox mix at any given depth. Let’s talk about Nitrox for a moment. When planning an open circuit dive on Nitrox, you will calculate the percentage of oxygen at the maximum depth of your dive to a partial pressure (PO2) of 1.4. So let’s say you are planning a dive to 30 metres, you would request a gas fill of (say) 34%.

Question. What is the POs of 34% on the surface? The answer is 0.34 and at 10 metres it’s 0.68, at 20 metres it’s 1.02 and at 30 metres it’s 1.36. Agreed?

Mark Lewis - Rosehill 2021
SS Rosehill 2021 - CCR Diving From Plymouth.

A CCR has a concept of a “set point” or in other words, your pre-set PO2. Let’s say this set point is 1.3. At 30 metres you will be breathing a 32% Nitrox mix and at 20 metres, 43% and 65% at 10 metres. So while an open circuit diver is still breathing 34% Nitrox at 10 metres with a PO2 of 0.68, the CCR diver is breathing 65% mix at a PO2 of 1.3 and offgassing more quickly.

There are a plethora of other benefits too but what are the disadvantages? To me it’s the whole “bagpipe of buoyancy” issue, where Boyle’s Law and Dalton’s Law of partial pressure play silly buggers. Where on ascent, your BC, drysuit and loop expand as you shallow up under the guise of Boyles Law, where that damned Daltons Law thinks it’s funny to squirt a chunk of O2 into the loop to maintain your 1.3 setpoint! #Bastard!

What Next?

Many people ask whether I want to become an instructor and at the moment, the answer is “no”. I’m enjoying the diving at the moment, be it open circuit twinset or CCR. I’d like to complete my CCR Trimix ticket to get a little deeper and with aspirations of a visit to Malin Head, maybe some future training. Diving has taken me to many corners of the world and I’d like to continue with travel. There are plans to revisit Chuuk for a third time and also the Great Lakes and Lake Huron. There are some fantastic dive sites in the UK and I include the English Channel, Sound of Mull and of course Scapa Flow for which return trips are already planned.