I'd love to see Telltale try out some new waters. I don't see this game as a fps-shoot&kill game, rather as a puzzle-game with a lot of cool cut-scenes.
And I hope they write the story with more sea-creatures than the Jurassic Park-series have presented previously.
Imagine the humans arriving to the Island by ship. During the voyage they suddenly feel a hard blow to the ship. Some seconds later the people witness a large creature jumping up from the water. Another creature can be seen on the surface, with the size of a bluewhale and huge razor-sharp teeth.
The sea changes color, as the humans witness the smaller creature getting ripped to parts by the
Predator X:

[Images Copyright: Natural History Museum, University of Oslo, Norway]
A few days after arriving on the Island, the humans have to enter the water to solve a puzzle (by diving, boat etc).
By combining creepy music, and knowing that these creatures are in the sea, I would be freaked out while playing that scene.
Another creepy seacreature is the Megalodon: