Going back and reading your post, it seems you mean something like making the ship stop where the character thinks it does, and I'm still not following because it's trivially true that the character thinking something does not make that thing true in the fiction.
and yet is what you said, isn’t it?
What makes it true in the fiction is everyone at the table agreeing it's true in the fiction.
yes, that would make it true, and we are back at ‘the DM says you know no messenger here’…
But who decides? If it's the player's choice to play their character as someone who's sane or someone who's delusional, then they are the one roleplaying their character.
I don’t follow, we just agreed that something is not true just because the player says so.
If it's the DM, then the DM is doing the roleplaying.
The DM does not say ‘your character does not search for ships, instead he goes into a pub’, he says ‘you find no ships’
I do not want the Sailor background dragged into this, I was talking about the Criminal, the two are different…
Because it's impossible to find out things about other planes before you go there? Even if you're a sailor who's spent years acquiring knowledge about various ship routes?
we are back to highly unlikely to the point of near impossible, since you ended up on a random world and did not anticipate this.
Also, you were a sailor in your past and you can consider yourself lucky if you traveled more than one sea / ocean in one world, there is no way you knew of ship routes on other worlds from your background.
Same for the criminal, you know a local thieves guild, that is it.
If you planned this trip, that is something different