"As I heard it, a Ship sailing over an area like that would lose Buoyancy and sink."
Gas from methane hydrates on the offshore shelf of the Carolina sea bed are considered a possible explanation.
Somewhere along the Scottish coast is an area called the Witches cauldron, considered a dangerous area by local fishermen.
The sea bottom in this area contains methane producing peats. There would be a sudden large methane release from the peat, resulting something like boiling or seething on the ocean surface. The gas bubbles lowered the weight/mass of water so that any fishing boats at the surface now weighed more than the weight of an equal volume of gas/water beneath it. Boats would sink to the bottom and not be seen again. A hard end in a dangerous job!
Then again, perhaps there is something else going on!
(Seriously....who would give this sort of thing to a child to read!)