Well, I just thought of a brand new fork in the game utilizing sunken treasure ships. You get a drop of a map, or rare sporatic vendor and it gives you rough cords' to the area of the ocean and after buying or questing for hand pumping unit to supply your quested deep sea divers suit, you can dive and recover treasure. This could incorporate enemies if need be. You would need a crew or npc to crank the air pump.or just straight up a treasure map, could by a way for the wonderful devs to do more with that tieor of drop, things that deal in treasure maps, you could even have a RNG made map with a random captain name (the one who made the map and buried the treasure, one of the locations of the sea and what kind of enemies are in this area.
all this could be from a new type of interactable table in taverns, a planing table where you look at the map and see where the treasure is, from this table you would go off to these locations (band new areas, not any of the buried spots) and you and your crew would go in and ether fight or do a puzzle (or both) in order to access the treasure itself.
this can be for the brand new (or some existing) legendaries BUT also would be a new system that the devs can use in the future for more treasure hunting
The idea other than the map idea of bogustree, is from an old dos game called 'sea rogue' that had over a hundred real located sunken ships and their accurate treasure that was found. You gained riches and competed with ai salvage ships and pirates.