Speaking as a female longtime sailor, for some reason I've always liked calling my boats "she" -- it makes them feel like best friends. And of course it's rather nautical and salty and makes you feel like a real ol'time mariner :-)
It does sound like just another variety of boysh*t and in theory I should object to it strenuously -- and yet it's a chink in my bristling antipatriarchal armour... I think fondly of my boat as "she" and don't even raise an eyebrow when I hear myself tell stories about "her". But I would never call a car or a bicycle "she". It's only boats -- especially sailboats which for some reason seem to have more personality than your average vehicle.
Should note that this curious nonsensical gendering applies also to tasks or jobs, as in the Canadian expression "gitterdun" (get 'er done) and Australian "she'll be right mate". In these cases the job or task may (icky thought) be reflexively compared to the "job" of seducing (to put it politely) a woman?
There's also a strange habit among Anglo men of a certain age (like, over 60 in my experience), of calling all cats "she" and all dogs "he" regardless of the animal's sex. I guess dogs are just more boyish than cats in traditional eyes?