All these boats with their off-label blue parts are junk.  Carracks are the only thing worth sailing, they vastly invalidate your old outdated boats at all levels.  Sorry if you "don't want a carrack", you have inferior gear, the developers should not be wasting any of their exceptionally limited time on giving handouts to people who intentionally want to play the game at a subpar level, or people who just want another get-rich-quick market scheme selling junk.

Go work on your carrack.

As far as I'm aware, the boat gear used to upgrade the boats, ex. Mayna Cannon, doesn't downgrade when you fail???

The other boat gear, such as the stuff you can get with Shakatu coins (or at least before they added the new Shakatu coins) was junk.

Besides, they're already giving you another mid-tier junk boat.