I use one of those 'flat' hoses and I store it on a plastic gizmo designed
for coiling up extension cords. This way I've got a hose that isn't limited
to just the style that comes in those flat ones with the reel. I also
connect the ends to each other to prevent spiders and other gunk from
getting into the ends of it. I've got a 50' flat hose on a bracket designed
for a 100' extension cord and it JUST fits. The width of the hose is about
double an electrical wire so keep that in mind. A reel designed for the
hose also usually hands squeezing out the water and probably stores a bit
more compactly. But then you're at the mercy of the reel working properly
and I've had plenty of them over time (at home) that always broke. Your
other choice is those coiled 'air hose' style. My only concern with those
is the spring tension they extert on the connections. This is OK if you're
just talking about hosing down the backyard but I'd be worried about it long
term for a shore water connection.

I also put a brass shut-off valve at the boat-end of the hose. I found one
with a 45 degree bend in it and that helps with the clearance to the shore
power cables also in the same locker. The shut off on the hose side allows
me to avoid getting drenched when connecting/disconnecting.