Reading your recent posts has been like dipping my bottom over and over into a bath of the silkiest oils and creams.
Taken literally, you land on a starfish space and take a starfish. However, once you put another ship on a crane in order to build, you can't garnish because you didn't receive the starfish immediately prior. This is an absurd result ...
I don't see why it's absurd. In your example, you could get the starfish and immediately place it on a tower space that you planned to build on later in your turn. You don't have to be next to the space to garnish it, if that's what you're thinking.