Like the first part of it wasn't technically in the ocean. But you know those sort of black and white-tannish "map/image" drawings and how some shows animated them, like say, the drawings on Maui in Moana, but in a very black and white-tannish "ancient map" style. That's how the first part was portrayed with.Like it started as a "drawing" of like the surface of the water with a ship and then animated to have a submarine going down and as it was going down, beside it had like "ancient writing"/words describing whatever ancient thing or whatnot.
And as you would expect, at some point, you know something feels off because the way the map was presenting itself, it was showcasing in a circling rotating way and when the map should've rotated back to the surface part, instead it showed the sub going deeper and deeper, like the map was changing off-screen rather than getting longer and longer. And as the sub went deeper and deeper, the more creepy the imagery and wording would get.
Like the words becoming more twisted and the imagery would feature more and more bigger and featured creatures showed up. And from time to time, there'd be this voiced narration of the ocean and of the deep. And like the imagery and wording, the narration would get more ominous and foreboding. It then ended with the sub in a very very pitch black void, then it entered the layout of the sub, and then the image "lit up" and there was this very giant creature outside the sub's window. It looked rather lobster-like until the imagery exited out of the sub and the creature became very hard to describe and looked very different and much bigger than what it looked like outside the window. The map then ended with the creature speeding toward the sub and then just a blank map.
After that part was done, when it came to the second part, it transitioned to rather classical book picture-esque styled drawings. Just black and white pencil-like drawings next to words like in a book. There were drawings of like different potential creatures possibly hidden under the ocean, with a common featured one being a giant sea serpent/eel-like creature. The narrator that was talking sounded like a person who was very knowledgeable or a survivor of a unknown creature out in the ocean. And it sounded like they were being haunted/hunted by this creature. The narration came across as very Lovecraftian, despite the fact that the creatures looked very straight-forward.
After the narration was done, it transitioned to a rather real-life setting with a bit of a black and white filter. There was still color, but it looked like it was from an old TV-filter or whatnot. The setting came across as very casual as the narrator was exploring a beach-setting with modern-day boats. The narrator was with some friends exploring a beach/ocean setting, but they came across as very worried and quite often, they would "see" this creature coming out of the water, with none of their friends seeing the creature and being seen as paranoid. The creature looked rather sea serpent-ish, mostly because there were alot of coils or what could've been a long body coiling, but whether or not it was a sea serpent, I don't know. And they come across as black-and-white and picture-esque similar to the book images.
It was mostly alot of casual stuff with the narrator and group exploring different areas, like beaches, marshes, the ocean, etc, with the creature being seen by the narrator quite a bit. Eventually, the narrator was separated from the group after what looked like a coconut crab or a crab of some kind started chasing them. After getting away from the crab, it then really started moving fast as the narrator is grabbed by what looked like an eel body, but was giant and didn't look like the main body. When the narrator was dragged underwater into a vast ocean, it didn't show the creature's head, but you could see what looked like flashing eyes just looking at the narrator. The creepy narration starts again and continues as the narrator gets dragged deeper down, with it looking like the creature has no intention of eating them and just dragging them deeper. And eventually, the eyes of the narrator closed.
