G'day Christine! How goes my favourite Bailey's lifter?
I think the imagination of a dozen people, mysteriously having survived the sinking and spooking around the sunken wreck in an air pocket sounds like a story for a creepy movie.
Already been done, hasn't it? Not with the
Titanic, but a fictional vessel in a miniseries? I still have unwelcome flashes of it when I'm diving wrecks and I look in portals. Can't help but recall the scene that has a diver look in a portal, only to be suddenly met by a face looking out! As ridiculously, laughably far-fetched as the scenario was, there was something terribly eerie about it. Something similar was shown in an episode of
Seaquest DSV, tied in with a ghost story. Of course you had to look past the plot devices such as the 'innovative' cover funnels that enabled them to make the ship air tight...it took suspension of disbelief to new heights, and that's before you even get to the supernatural elements. Still, that last scene with the ship lit up on the bottom of the sea had its own creepiness. Some (smaller) wrecks in tropical waters are illuminated from within at night by bioluminescent 'flashlight' fish. I've never seen it, but have heard descriptions from those that have.
You're not far off with your description of what happens to the body's cavities at depth. Barotrauma - pressure related injuries - are one of the first lessons taught to a scuba diver. Failure to equalise your ears and sudden pressure changes can result in injuries even at comparatively shallow depths - shore divers are warned that even large waves going overhead in shallow depths can cause inner ear barotrauma. Of course, the situation isn't quite the same as it is for free divers or those sucked down in a shipwreck, as divers are breathing compressed air at the ambient air pressure, which then expands if trapped (say in lungs, sinus cavities etc) as the diver re-ascends. However, most people would be familiar with the effects of pressure on the ear if they dive into deep water - it is necessary for free-divers as well as other divers to constantly equalise the pressure in their ears. Failure to do so results in at least discomfort, and at worst inner-ear 'squeeze' and finally a rupture. Discomfort may be alleviated temporarily as the blood fills the cavity and achieves equalisation.
The most radical change in pressure occurs within 10 metres of the surface. Above that we have one Atmosphere of pressure. At 10 metres that is 2 atmospheres, at 20 meters it's 3, etc etc. So within that first 10 metres, the pressure has doubled.
Those who were sucked down would have experienced noticeable discomfort in the ears primarily - it is necessary to equalise every few feet, and I doubt that they were doing this. However, as they would have been drowning or suffering debris related injuries, I doubt that this was paramount for them.
