Hmmmm. Suppose the range was S and it could only eliminate up to one mast, in addition to my suggested wording change. Would look like this:
Once per turn, before you give this ship an action, roll a d6 for every ship within S of this ship. On a 5-6 eliminate a mast from the target ship.
That sounds much more reasonable, though the cost might be too low. (not sure where to put it without testing)