Fallout 4 is so full of content, it is nearly impossible to walk more than a minute in any direction before without stumbling upon a point of interest. That is, unless you decide to hit the bottom of the ocean where you can enjoy more than 30 hours of nothingness.
One Fallout 4 player has spent more than 30 hours exploring the bottom of all large bodies of water in the game, only to discover that they contain almost nothing.
Reddit user Lavonicus spent most of his free time exploring and documenting the ocean depths of Fallout 4. After spending more than 30 in-game hours under the water, he charted a map of all the areas of interest (hint: not much), snapped 113 screenshots and created several YouTube videos.
"If you are looking for massive amounts of loot and underwater vaults you will not find that here," Lavonicus concurred before vowing to repeat this effort for every new Fallout 4 DLC. "If there is water, I will be there and I will explore it you can count on that."
Lavonicus noted that Fallout 4 original concept art contained underwater content and that modders have found evidences of a harpoon gun that was cut out from the game for undisclosed reasons. He believes that these will eventually make it to the game and he is determined to find them as soon as they do.
Somehow, we doubt that Bethesda will add harpoon gun and underwater vaults to a DLC without marketing it to hell and back.