Can ghosts exist underwater?
Theoretically, yes. However there are numerous factors that would come into play during this type of catatonic existence. Evidence that I have studied suggests that although the ghost still exists, it does so in a comatose or suspended animation type state similar to a cryogenic suspended stasis. While dormant in this sleep-like state the ghost is unaware of the passage of time and/or events that are around them. However, when remnants of shipwrecks and other maritime tragedies are taken from the site of the incident this action can now potentially awaken the energies via a catalyst, conduit, or trigger mechanism. These energies which would be attached to the recovered items would have been disturbed from their sleep, thusly causing a haunting that would be associated with that particular item.