But something is missing.
No matter how much of the ocean floor you survey, you will not find something you can find just about anywhere on land, (even if it is rarely)
PokéLoot
Now, I made this suggestion a long while ago, but it looks like the suggestions forum was completely reset, and the last time i posted was a few years ago.
Anyway, the idea is to make a type of Pokeloot that is meant to be used on the ocean floor, or in lakes and rivers. The item, when placed would be just like any other PokéLoot ball, except it would be submerged in a block of water.
This would allow it to spawn on the ocean floor, without there being a super noticeable air bubble around it, that way, you would actually need to be riding a water type pokémon or using potions to properly search for them.
The things they contain would be related to water type pokémon, they could be relic type items from past sunken civilizations, etc.
There was definitely underwater pokéloot in the games. (Seafloor Cavern and using the Dive HM on dark spots in the water come to mind)
Thoughts?