Belemnite Diver Blog

Blog Moved

Thu, 15 Oct 2026 10:45:00 +0000

The blog has moved back to being self hosted and off BearBlog. Largely due to Bears insane policy of shadowbanning paying customers. This probably means nothing to anyone not me, so don’t worry more diving and CCR posting coming soon.

CCR Dive report - SS Iolanthe

Tue, 06 Oct 2026 18:39:22 +0000

The Steamship (SS) Iolanthe was an armed steam driven cargo ship that was torpedoed by German U-Boat UC-75 about 10 miles off Portland (UK) early Jan 1918. Having being hit in calm seas, she turned and tried to make for a safe port but took on too much water and was abandoned by the crew who survived. Apparently UC-75 was later sunk near Yorkshire having engaged with a convoy and being attacked by HMS Fairy who also sunk in that action.

CCR Dive report - MV Aeolian Sky

Fri, 02 Oct 2026 10:55:00 +0000

Finally back in the salty stuff recently. Had one good day (described below) and one day of the worst sea I’ve ever been in and we won’t be talking about how that went - it was so bad at one point I threatened to take up golf!

The MV Aeolian Sky was a Greek transport ship, launched in 1978 and a year later was heading down the channel from London to Dar-es-Salaam loaded with various cargo when she collided with another boat.

Checklists and rebreather diving.

Fri, 28 Aug 2026 10:19:23 +0000

I read ‘The Checklist Manifesto: How to Get Things Right.’ by Atul Gawande a few years ago, and again more recently and on both occasions I was struck by its relevance to CCR or other deep technical diving (and even diving generally).

The book, as the name suggests, makes the case for how valuable checklists can be to ensure that no matter how confident you are in the process, having a list to follow is a good way of avoiding errors and catching problems early. The books use cases focus largely on medicine (the author is a medical doctor), construction and aviation but apply just as well to diving and especially CCRs with an extended number of preparation steps.

The sound of silence - and being screwed by UK weather.

Tue, 14 Jul 2026 10:16:44 +0000

So been a month since I posted and that was kinda a boring entry, as might well be this one.

Two reasons - one, no one reads this anyway, so I don’t feel any great urgency to post. Two, and this is by far the bigger of the two, my diving has been very limited the last couple of months.

After Scapa and diving the German fleet quickly came June and a number of family commitments as well as a non diving holiday. Into July and I had a quarry dive to check over the SF2 and get some squeaky trimix for what promised to be an excellent weekend of reasonably deep diving on the South Coast….

All divers need a 3d printer

Fri, 12 Jun 2026 15:39:49 +0000

Dive manufacturers seem to have a relentless enthusiasm for making things hard to take apart to service. I assume this is so you’ll pay the money to become a proper service tech and to protect the income of those that already are. For regulators and tanks I’m largely on-board. Give me someone who knows what they’re doing and I’m happy to pay, but for so many other things that just need removing, replacing or tightening the lack of tools can be a major pain in the backside.

Diving Scapa Flow (Part 3) - UB-116

Tue, 19 May 2026 18:52:00 +0000

In addition to the sunken German fleet capital ships like the Coln, Karlsruhe, KronPrinz and so on, there are other wrecks in Scapa Flow with their own stories to tell.

One of my favourites is the UB-116. As the name suggests, she’s was a WWI era UB class submarine. She was commissioned right at the end of the war in May 1918 launching from the Blohm and Voss yard in Hamburg. On 25 October 1918 she left Heligoland for Scapa Flow, at this point in the war the regular enlisted men had already started to mutuny but the German authorities wanted to show that power still existed in the fleet and launched a final attack on British warships. The U boats were intended to be the tip of the spear of any attack and sink a large number of British ships.

Diving Scapa Flow (Part 2) - SMS Karlsruhe

Tue, 12 May 2026 19:08:24 +0000

Diving Scapa Flow (Part 2) - SMS Karlsruhe

This is a pretty regular ‘shake out’ dive in Scapa Flow as its shallow and more broken up than some of the bigger ships, despite that, it’s still one of my favourites. The shallowness means better light and a longer dive (the cold really is my limiting factor) and as I’m normally pretty navigationally challenged, the layout helps me actually find and identify bits.

Diving Scapa Flow (Part1) - getting there

Mon, 11 May 2026 18:26:42 +0000

Diving Scapa (Part1) - getting there

Almost any diver who loved wrecks should (if they don’t already) consider Scapa Flow as a ‘must do’ destination. The sucken German Imperial fleet is the main attraction but given the Flows use in both World wars as a deep water anchorage for the British there are plenty of other things too. I’ve been lucky enough now to visit Scapa Flow on a few occasions but only now blogging about my last trip.

Diving the HMS M2

Tue, 21 Apr 2026 12:53:00 +0000

Having written back in Jan about the trials of owning a rebreather, I was finally glad about a month ago to get everything back in a fully working and tested condition, all I needed now was to go diving! As with last year, work continues to drive my stress levels to new heights and thus the responsibility for organising this trip largely fell to my lovely girlfriend to sort accommodation and drive me around as she could then leave and go enjoy Dorset and Devon when I was sat on a boat. She, as normal, did this excellently and now all dive trips will need a hot tub!

Coding a dive calculator (some assistance from Claude)

Thu, 26 Mar 2026 13:29:07 +0000

I had a long standing project kicking about on my hard drive and work is allowing me and my team to burn some Claude code credits, so I decided to run my poor quality html and javascript through it and see if it could add some extra features I’d not gotten around to. The result is

The Belemnite Divers Dive Calculator

Now I’d say about 85% of this was my original work although the code got cleaned up. 15% is pure vibe code. I take 0 responsibility for how people use it, you’re divers and should be trained on all these calculations without using my random project.

UK Wreck diving and the Protection of Military Remains Act

Tue, 10 Mar 2026 19:27:00 +0000

As a keen UK wreck diver, the last few days in between work and some BSAC pool training, I’ve been contemplating how badly the government will screw me again, but also coming to the conclusion that divers have screwed themselves. The BSAC article at https://www.bsac.com/news-and-blog/the-protection-of-military-remains-act-1986-and-the-armed/ lays out the basics and my own thoughts are below.

It must be said, British diving has an annoying history of knocking bits of shipwrecks and then them ending up in someone’s man cave or garage. I had hoped the British diving community had learned to be better, but it would seem the gung-ho fucking ignorant mindset remains in some divers. For the avoidance of any doubt, I’m of the opinion that bits of shipwrecks should be left on the shipwreck unless respectfully removed in the service of a museum. As with sites on land that might be the site of a critical battle of the civil war, say, you may go see them, even walk across the land but don’t turn up with a shovel!

A return to BSAC and instructing

Sat, 14 Feb 2026 16:21:58 +0000

At the end of 2025 I was feeling a bit like the year had been pretty ok for diving, I’d done Orkney (bits of Scapa and some outlying islands). I’d done the Thistlegorm in Egypt which was well worth getting up and leaving my other half at 04:30am. I’d done my MOD2 in Malta, which while far from perfect, had really given me an even deeper appreciation of CCR diving and I’d had a few nice dives on the South coast, even though I’d spent most of the summer (and pretty much winter) suffering from work created stress. One thing I hadn’t done was teach diving.

I love CCR diving, but…

Fri, 09 Jan 2026 13:33:22 +0000

I love CCR diving, but right now the entire loop hose and DSV is in pieces on my desk (inside, the garage workshop is too cold). I’m replacing the o-rings and the mushroom valves. Putting new o-rings where new o-rings need to be. Probably replacing the mouth piece. I’m also replacing one of the hose pieces as it has a slight knick/dent on it and I’m not risking it.

The head unit is also open, I’ve delayed sending the computer in to be serviced and have a fix applied for too long, so that has to happen as well. New o2 cells have been ordered. I don’t strictly need them but I almost missed out on a Scapa Flow trip because I ran out of spares and I’m not chancing it again. I need to order sofnolime. I have a new inflator hose to fit. Two of my 3l tanks need a hydrotest and o2 clean. I then need to go get Helium with my buddy and blend some trimix to go in one of them. Do I replace the other o-rings - might as well I suppose it’s been a couple years. This is probably more maintenance and cost than my old twin set cost me in 3 years (test aside). That said, come the warmer months I’m hoping to be sitting happily at 40-60m seeing interesting sunken history and the occasional fish if it gets in the way!

The U322

Wed, 19 Nov 2025 00:00:00 +0000

A dive? In November? On the South Coast, the day after a storm? Sure, in the long list of questionable decisions I’ve made over the years, this might be quite a long way up there. Even more so doing it in a single day with 6ish hours of driving.

I’d missed out on this wreck in the summer and when a seat came up on a FB group, I thought ‘what the hell’, I had squeaky trimix sat on some tanks, I have fresh bailouts with deep and deco mixes and I’m sure I can put together the rebreather in time. Then Storm Claudia blew in and I blithely assumed the skipper would cancel and made plans to meet a friend for coffee. Skip to saturday afternoon, skipper has confirmed its going ahead. SF2 is assembled, gases have been tested and everything is go (and friend re-scheduled).

Sweary rant on CCR social media people and safety

Sat, 01 Nov 2025 15:48:00 +0000

One of the issues I have with social media involving rebreather divers is the dramatic willy waving that goes along with it. Every diver is a bit like this, but CCR divers are an especially terrible version of it - all their units are better and bigger and go deeper than everyone else. This also comes with a certain type of cowboy mentality that bad things won’t happen to them and their mighty unit. Now personally - my unit is long, thick and made of carbon fibre but I quite like not dying when I go diving, so would rather lean on the side of caution when things go wrong.

MOD2

Thu, 09 Oct 2025 08:59:00 +0000

Mod2

The next step in my rebreather learning is the 60m trimix course. Its name varies between agencies, but it is widely called MOD 2 (after the 45m MOD1). SF2 instructors seem fairly thin on the ground, but I was able to get in touch with an instructor in Malta.

I’d been to Malta before so knew the basics of how to get around, and although I did dive on the previous occasion, it was a small rec level dive. This time I hoped to see some of Malta’s famous deeper wrecks.

Making a 'Hydro modded' Casio F-91W Dive Watch

Fri, 12 Sep 2025 17:13:00 +0000

For anyone even slightly ‘into’ watches, the Casio F-91W needs little introduction. It’s the quintessential cheap digital watch. Sold into the Billions and seen on the wrist of everyone from Obama to Osama. (In)famous as having been used as a cheap and accurate timer in IEDs, it’s said anyone wearing one during the War on Terror in an American airport had a higher probability of being pulled over for that extra special attention.

On Dive watches

Thu, 04 Sep 2025 12:43:00 +0000

On Dive watches.

One of my few (lol) kit obsessive tendencies is for dive watches. For other divers its torches, for some its masks (wait I have that one too), for me after my general diving kit, its watches. I like a nice watch, be it a dive watch or a dress watch.

A Shearwater Petrel with cable for a rebreather like the SF2 is around £1400 at the time of writing. So two of those will be £2800 which is still considerably less than £3680 which is the current price of the Tudor Pelgos FXD allegedly used by the French Marine Nationale.

The P555

Fri, 15 Aug 2025 16:45:00 +0000

The P555

Had this booked for a while, but a nice midweek dive was just what the Dr ordered at the moment. Having first managed to silence my work anxiety and lose 30bar of trimix to a leaky inflator (fixed) I was off down the south coast for the day. Fortunately the M5 was kind to me and I arrived early to park up, sit in my car and question the decision to do this in a day, especially at the moment.

Why the SF2 (Part 1)

Mon, 04 Aug 2025 15:24:00 +0000

Why the SF2?

My rebreather experience started basically at the same time my ‘technical’ (other than nitrox if you count that) diving did. As I was starting to look more at twinsets and accelerated decompression I got to do a BSAC ‘Try Rebreather’ day at Vobster (an inland dive site) with some friends of mine.

First off I tried an AP Inspiration. I will say the lovely BSAC instructors ignored me telling them I needed X amount of weight even with a big steel twinset, so I was underweighted when I went in. This resulted in me sucking the loop empty every breath to try to control buoyancy, having the ADV fire and a horrible feeling of being near death. I essentially hated every minute of the dive.

3D Printed SF2 loop caps

Mon, 04 Aug 2025 11:49:00 +0000

I am a menace with my 3D printer. I really wanted some loop end caps to seal my loop when I’m not using it. This comes after the last time it had been sat on my work bench for a while, I set everything up, did a pressure test and started coughing. Understanding that either my just filled scrubber had not been sealed (it was) or the counter lung was dusty (it wasn’t) then the only remaining thing was my loop. As always I’d sterilised the hell out of it and let it dry after it was last dived, but maybe dust or something else had gotten in. I washed it down again with Chemgene and all was well on the dive the next day. Hence trying to find endcaps, as no one else seemed to have done this, and I couldnt get other branded rebreather ones to fit (what mutant size is the JJ!?) I made and designed my own. Get yours at Here

Problems with UK Diving (Part 1 of lots)

Tue, 22 Jul 2025 17:01:00 +0000

Every single UK based diver, skipper and dive boat owner/deckhand and dog I’ve spoken to, says the same thing. UK diving is dying off. Having just come from a days diving a sports diver level wreck on the south coast that was only dived by what you would probably class as ‘technical’ divers, I’m finding it hard to disagree for reasons below;

Problem 1.

The weather. Honestly does this need elaborating on? The weather in the UK has cost me so many dives, lots of hours at home or going to the local quarry rather than diving a tasty wreck because the wind/rain is too much. Even when I’ve made it out - I’ve seen people puking, sunburned and soaked to the skin. Basically good days diving on calm seas in mild temperatures is a UK rarity.

Why a blog?

Tue, 01 Jul 2025 17:26:00 +0000

Why blog? Mostly because I’m totally sick and tired of social media and wasting time on it. If I can spunk my thoughts onto the internet it moves me away from Meta controlled BS apps and makes me write something. Getting people to actually read it on the other hand is a totally different proposition. The algorithm now dictates peoples life to such a degree that its hard to find small subgroups of people with shared interests… none the less…here I am blogging about SF2 CCR and probably some general dive stuff, 3d printing and random stuff.

Mon, 01 Jan 0001 00:00:00 +0000

British technical diver - largely diving an SF2 eCCR.

BSAC Instructor - open circuit diving.

Likes wrecks and cake. May talk about 3d Printing and watches.