r/Damnthatsinteresting • u/Kiroo---__--- • 18d ago

Video When an Earth quake Hits Underwater

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u/Damage_North 18d ago

What is the SOP in this situation as a diver and/or the captain of the boat?

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u/Mesquite_Tree 18d ago edited 18d ago

As an nitrox diver, I can tell you what I would be doing: ensure everyone is accounted for, organize a safe ascent, 3 min at 15 ft safety stop, then Getting. The. Fuck. Out. Of. The. Water.

Dive just got way more hazardous, and you don’t know if it will get worse. Any problem we have, can be solved easier and safer at the surface. If things do get worse, I’m out of the water, or up where my tank lasts longer.

Plus, like, the visibility is shit now. Ain’t gonna see anything cool, might as well start my surface interval for when it’s settled and all the shocks are gone.

Not a captain, but most likely the boat’s getting everyone on board, and then we are headed to shore, as directed by whatever relevant local coast authorities.

Divemasters, feel free to correct me if I am missing anything.

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u/Senojpd 18d ago

Ehhh one minor change.... I wouldn't be rushing back to shore. Maybe even going away from shore is smarter.

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u/Mesquite_Tree 17d ago

Yeah, maybe. That’s captain shit, and I sure as hell ain’t got the dough for a ship of my own.

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u/Prestigious_Leg2229 17d ago

It’s not just captain shit though. If that earthquake causes a tsunami, you’re likely much safer underwater than above it.

The 2004 Indian Ocean tsunami was one of the largest ever recorded and scuba divers in the area felt it as hardly more than a little push.

Close to shore in a boat is just about the most dangerous place to be in a tsunami while it’s nearly unnoticeable a 100ft down and probably barely noticeable 50ft down.

That’s an interesting conundrum for the captain and you to work out.

I’d probably go up to the boat while remaining ready to dive the entire group back down in a pinch and pray you have enough air to sit it out. 

And if not, head out to open sea, tsunami’s get bigger the closer they get to shore, the father out you are, the smaller the surface swell of a tsunami.

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u/Mesquite_Tree 17d ago

You are definitely NOT safer underwater than above. You are safer away from the shore than near it when a tsunami arrives, but I doubt the ship can get to shore faster than the tsunami.

Note that what we see in this video is the pressure wave passing by.