[ericthered]

Also, remember that a merchant navy and a military navy have different requirements. While a merchant navy may be able to get around with just wind wizards, a military navy will need to be able to handle being outgunned by enemy wizards (or even just dealing with parity)

The wind spell is actually really cheap to cast: a 50 yard radius for an hour is a single energy point, can be cast with just magery 0, and requires only two spells past the basic set. So in some ways its an ideal career for a lazy (or talentless) Magery 0 individual. A skill of 11 may even be sufficient to be effective.

But banestorm campaigns tend to have varying levels of magic, so a lot depends on that. Ships of essential wood are probably over the top, as are a number of combat applications, but there is no reason not to hire a wind wizard. There is also room for a magical tradition of ship's wizards that teaches those kinds of spells.