Question How Do They Choose and Prepare Ships for Wreck Dive Sites?

[Miyaru]

New wreck in Gozo, Malta

On the 10th of February 2018, the oil tanker M/T Hephaestus was wrecked on the shore at il-Ponta tal-Qawra, off St. Paul’s Bay in Malta at 6:15am. According to the accident report (attached), she had been dragging her anchor since 05:30. At 0600, windspeed was 35.5 knots with gusts up to 52.7...

scubaboard.com

This thread has some videos of the sinking of a prepared shipwreck.

Ship makeover:
The preparations took months: cutting open the decks in various places to minimize the risk of getting trapped, fixing doors in an open position or completely removing them, cleaning all the oil and grease (which was the most time consuming).

Picking the spot:
The location was debated for a long time as well. Once the final destination was determined (outside of shipping lanes, outside of fishing areas and outside of marine protected zones), several surveys were carried out at the destination site to map the seafloor. No sea gras, no rocks, smooth surface to ensure a stable position.

The Rules:
Yes, there is a lot of red tape. One roll of red tape for each government department. If it's good for the ocean remains debatable as there are always environmentalists who claim it is unnatural. On the other hand, it is surprising to see how fast the sea embraces a new wreck, overgrows it and turns it into a new home for lots of fish.

Why do it:
Because it's fun and because we can. It's a tourism attraction and an almost empty stretch of sandy bottom was turned into a shelter for thousands of fish.


You mentioned the new wrecks in Thailand. If you plan to go to Koh Tao, do a dive on the HTMS Sattakut. You will see what the sea does with a wreck in just a decade. It was scuttled in 2011, but glided away from the intended spot while she sank. A short while later, hard-hat divers lifted the wreck just a little off the bottom with commercial liftbags. A vessel towed the wreck to the intended position and there she was put to rest on the seabed.

 

[Gandalf-the-Diver]

It would be nice if we could get something chonky to dive on in Puget Sound, and I know of a few ships that would be candidates, but it's hard to think of a really good spot around here. Deep, but not too deep, good vis, low current are not normal conditions in the sound.

There are quite a few artificial reefs, just north of you in British Columbia.

 

[Gandalf-the-Diver]

The Artificial Reef society of British Columbia, has sunk a number of ships in the waters off BC. They have also acted as consultants with projects all over the world, including down under I believe. Here is their web site: ARTIFICIAL REEF SOCIETY OF BC
I watched the HMCS Columbia, when it was blown up to sink, by Campbell River.

 

[Gandalf-the-Diver]

It's something I'm a little curious about, although I suspect it's often not as complex or interesting as it might first appear.

Is the ship actually being sunk, because it's motivated by creating a reef and a dive site for scuba-divers? Or is it being sunk, because disposal would be expensive or complicated? Or is it being sunk because it's the government and they can just get more tax-$, and salvage reduces the amount of money that pads congress's pockets with MIC money. Each sunk ship, is another ship that can be justified being built. (I'm not trying to get too political here.) My guess is the reef cover-story isn't really why ships are sunk.

I would expect you'd want to at least drain any oil, gasoline, or known toxic chemicals, and that's probably done in the US anyway.

The Artificial Reef Society of British Columbia, has sunk a number of ships, off the west coast of Canada, for the purpose of diving. Holes are cut in the hull, to facilitate penetration and egress of the wreck, in addition to sanitizing it. All the wiring is removed, anything that could become a snag hazard for divers, is all removed. All fluids, asbestos, anything that is a hazard to marine life, is removed. The rules are quite stringent.
Then the put on a big show, and blow holes in it with explosives, and sink it. I watched the HMCS Columbia, destroyer escort get all blown up. I did not dive then, but I look forward to the day I can go dive it. It was sunk in 96.

ARTIFICIAL REEF SOCIETY OF BC

The Artificial Reef Society of British Columbia (ARSBC) is a registered non-profit society based in Vancouver, British Columbia, and is a registered tax-deductible charity in Canada.

www.artificialreefsocietybc.ca

 

[WeRtheOcean]

cutting open the decks in various places to minimize the risk of getting trapped, fixing doors in an open position or completely removing them, cleaning all the oil and grease (which was the most time consuming).

Of course, ships sunk for different reasons -- meaning in war -- don't get that kind of pretreatment. Is there data on how those wartime wrecks affected the environment?

 

[Cthippo]

Of course, ships sunk for different reasons -- meaning in war -- don't get that kind of pretreatment. Is there data on how those wartime wrecks affected the environment?

Yes, they often start leaking years later and require extensive remidiation. There are three that come to mind off hand, two in Canada that required hot tapping and pumping of remaining fuel when they began leaking, and another in Puget Sound that is a vessel of concern for that. All were post-war wrecks, but the same principals hold.

For a WW2 specific example, look at the USS Arizona still leaking bunker oil to this day.

 

[LightBrownPillow]

Not directly related to your question, but turns out there's a whole community of deep-sea life which thrives on "woodfalls", and have made great use of sunken wooden sailing ships throughout history.
Really cool to see how life in such desolate places will adapt to any energy source and stable structure they can find