Can this ship use the ability on itself? (As written, it can.)
Also, basing it off a move action creates some odd interactions with other move-based abilities, like Captains, which could still technically function even when using this to repair. Is that intentional? If not, it would be better to make this use a Repair action, with the added condition that it can be used anywhere rather than just at home or with a Shipwright.
I didn’t intend for the ship to be able to use the ability on itself, should have specified any other friendly ship.
It is also not intentional to be able to use a captain with the ability.
Instead of tying it to a repair action, would tying it to an action in general work? Something like this:
“Instead of giving this ship an action you may repair a mast on any other friendly ship with a point cost of 10 or less.”