We had some great fold up bikes on the boat. Used them all them all the time. Ride into town,bring back shopping, eccentric if we weremoored at end of port.
They weren't cheap, but lasted the distance. Salt water spray and rain etc.
Wd40, kept em going. The flat three was an issues, but was easy with practice.
they weren't the ones with tiny wheels, nor the full size mountain bike ones either. Just good adult size with a good size wheel. Foldedup to bag, but we left them on quay, chained up when in port. I wish I had them in our camper. Make it easier to seethe towns cities etc. They folded easily into bag. Dust kept out then.
I always wanted one of the full size mountain bike ones, like the Mantoba brand, but at the time were too expensive. But for ease of travel were awesome.
Though we don't have kids, if they are young, its great way for them to keep up with you for fast walking.