I have the blue tassles and when I try to board the ship it just says: Think again..

fuck this game

edit: now I have 2 blue tassles and have tried several ships.. but nope.. seriously what the fuck. why does this game hate me?

You're not on a horse, by chance?

You can only use one method of transport at a time. So you have to dismount from the horse in order to board the ship.

And if your plan was to take the horse with you, I get how frustrating that is.

fuck me that was it! It seems so obvious that you can't enter 2 vehicles at the same time the horse being considered one.. man that was annoying

It's not hate. It's rather how old games show its love :)