[Buzz]

Vessels in general have historically been assigned female by their (mostly male) owners. Ships, planes cars, etc. It has to do with the passion and affection that the owners have for their vehicles. Typically, men are more naturally inclined to feel and express love and affection towards entities of the female persuasion and find it awkward to do so towards something masculine. It's not as serious as it all sounds though - hardly a big deal at all. Women do the same in their own way. I once knew a beautiful Norwegian girl who called her car "Sven".