Thankyou to all those who answered (and may yet answer) my questions about the deep parts of the ocean. I’ve a few more that I’ve thought of.
First of all, where is the world’s deepest known shipwreck? The Titanic seems an obvious candidate, but I suspect that there may be sunken ships (or submarines for that matter) which have come to rest at even greater depths than that ill-fated vessel. I have heard, for example, that the HMAS Sydney, an Australian naval vessel which was lost off the coast of Western Australia during the Second World War (and whose wreck has admittedly yet to be found), was thought to have gone down in waters over 5000 metres deep; can anyone confirm or deny this?
Is it possible that there may be wreckage lying at the bottom of the Marianas Trench, the world’s greatest ocean depth? After all, a battle was fought between the US and Japan over the nearby Marianas Islands during the final stages of World War II; is it at all conceivable that ships or planes involved in that might have gone down over the MT (or was the battle conducted too far away from that location for this to be likely)?
Also on the subject of shipwrecks lying several kilometres below the ocean surface, is it likely that any bodies contained in such wrecks will be largely preserved in their original condition, even after the passage of many decades? (According to some people, the bodies of those who went down with the Titanic had still not completely decomposed when the wreck of that ship was discovered over seventy years after the vessel had sunk.) I have heard conflicting facts relating to this thing. On the one hand, some think that the almost freezing waters of the ocean depths would hinder decomposition to such an extent as to effectively stop it. On the other hand, however, even down there, there is apparently no shortage of scavengers ready to pick clean the body of anything that dies and comes to rest on the ocean floor. (I saw an excellent series on the ocean called “The Blue Planet” which, in a couple of instalments, showed what happened to the carcass of a whale that had descended to the seabed. After it had been lying there for about a year, only its skeleton was left (thanks to the attentions of hagfish and other deep-sea scavengers), and even that was in the process of being broken down.)