Mermaids, sirens, krackens, and more. Why not? Why can’t these be entities of the sea? Entities and spirits aren’t confined to dry land. Life isn’t confined to dry land. The ocean is a big graveyard not just to creatures of the sea but people. Plane crashes, shipwrecks, ancient events like tsunamis. The ocean holds many secrets, living and dead. Watery graves, accidents, murders, and more. Why should spirit not reside there? I would expect ghost sightings and paranormal experiences. Besides we don’t know everything about what life the ocean holds.
I imagine sirens to be one of two things. The first being a type of spirit looking to claim lives no one said the legends of demons were only for dry land. An actual creature is a possibility why would extraterrestrial life be only limited to dry land as well. Ufo sightings happen plenty around oceans. Krakens sort of remind me of an extremely large octopus, who says there isn’t something in that family that large that lives in the depths of the ocean. Perhaps they were a remnant from a prehistoric ocean but have now died out and that is why we no longer have accounts of these encounters. Just like I believe there was something to the stories of dragons throughout parts of the world. Mermaids are another entity I figure holds some weight though they are likely less malevolent than sirens. Also, why should the theory of dimensional travel not include the ocean? Spiritually speaking if portals are a thing on dry land I would assume that goes for water as well.
Who is to say that ghosts don’t wander the ocean as they do everywhere else? Watchers are entities that are around the sights of murders and graves, there is no reason they wouldn’t dwell in the depths of the ocean as well. I am sure many ships and people aboard them have many encounters while at sea. Then you have to think about places like the Bermuda triangle. I would like to know accounts of the most haunted oceanic locations. I would love to watch that paranormal investigation, where they stay on a ship in a location people say not to stay because of activity. Put some paranormal crew out there, throw an anchor and let them have a ship lockdown for 3 days, that would be entertaining besides I would love to see any evidence. I know most would be confined to the ship and surface of the surrounding water but it would be worth a go. I am not talking haunted ships here but haunted sea locations. Challenge: stay on a ship in the heart of the Bermuda triangle for 3 days. That could be so cool.