You live the life of the sailor, but the skies are your seas. Airships are the places where you feel most at home, soaring above the hubbub of the world, isolated in the freedom of flight. You might have served in the military as a scout or in some sort of sky navy, you might have worked for a merchant captain or passenger vessel, or perhaps you were a sky pirate who raided the ships of others.
If you decide to take the Sky Sailor background, you have proficiency in vehicles (air) instead of vehicles (water). In addition your Ship’s Passage feature applies to airships instead of seafaring vessels.