Belemnite Diver Blog

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.

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!

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 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!

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).

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

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.

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.

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

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.