Can you reveal a face down UT such as Runes of Odin to play it from your home island after unloading it there, or do face down UT’s have to be on ships in order to be revealed and used?
Unless the UT specifically says it can be used or applies while still on an island (Altar, etc.), or is revealed when unloaded at home, once it’s on your home island you can’t use it any more.
When you dock at home with a facedown UT that isn’t required to be unloaded as part of its ability, you can choose to keep it on your ship, but must state that it’s a UT. You don’t have to reveal which one it is specifically, though.
In multiplayer games, is gold on sunken ships revealed when it’s removed from the game? Or do you have to rely on asking the player whose ship sunk what they had on it? (this could be very important to know if something like Runes of Loki is still in play vs. gone for good)
Unrevealed treasure that’s removed from the game by sinking or any other means remains unrevealed. The player who lost the ship is free to tell you what was on it, but they’re not required to.