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Comment by Johnny555 | Hacker News Reader

Opening flooded compartments is not done lightly, you need to stop the source of the leaks first before you can open the hatches and enter the compartments and do a full search.

A collision between a 10,000 ton destroyer and a 20,000 (?) ton cargo ship dissipates a lot of energy into the water and churns up a lot of turbulent water, if someone fell into the water in the dark, it's not at all surprising that they'd be unable to surface. A human loses buoyancy around 30 feet deep in the water so if you're pulled 30 feet down in the dark, it can be disorienting and hard to figure out which way is up.

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> A human loses buoyancy around 30 feet deep in the water

Learned something new today, thanks for that. Didn't even realize this was possible.

Learned something terrifying today, is more like it. No wonder those big wave surfers talk about being unable to tell which-way-is-up when they get washed up by a wave.

The science behind it is really interesting. I had always assumed that you'd get more buoyant as you went down and the pressure got higher; the thing is, buoyancy isn't about pressure as such, it's about relative density. Water is almost completely incompressible; even miles down, its density only increases by a few percentage points. But the main thing keeping humans buoyant is the air in your lungs, and your lungs are compressed as the outside pressure rises, making the airspace smaller and denser, until your average density is greater than the water's and you sink.

Yeah, I looked it up for the same reason, that's why I said I found it so interesting :) thanks for mentioning it though, I'm sure people will be interested to learn why.

Thank you for the explanation. This is entirely counter-intuitive to me.

Is it a speculation suggesting some if not most are actually in the flooded compartments? Perhaps I didn't see this part in the articles I have read so far.

Since the missing crew are still missing, it's speculation that any are in the flooded compartments, but some of the flooded compartments are crew berths:

Monday's collision east of Singapore was the second involving a ship from the U.S. Navy's 7th Fleet in the Pacific in two months. The Navy said "significant damage" to the McCain's hull caused flooding in adjacent compartments, including crew berths, machinery and communications rooms.

It is speculation, but unfortunately it's also the most likely scenario.

    - Crew berths were at the primary impact point, so are almost certainly sealed at the bulkheads by damage control.
    - Incident occurred at 5am local, when you'd expect berths to be popular.
    - Sunrise is 7am local, so it was dark - so you wouldn't expect to have any unnecessary crew topsides (precisely because finding MOBs in the dark is near impossible) - and you'd hope any that are, have protective or flotation equipment.
    - You'd also expect that 10 people running around on deck would have had a much better chance of spotting another ship.
    - The proof is in the pudding - for not one of them to have been spotted in one of the world's busiest corridors, doesn't bode well.

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