You think you can't take it with you? Think again. The Montague high-performance Crossover bike ($399) folds up and fits in a bag in less than 30 seconds, which means you can go from boat to bike when you hit the shore in the blink of an eye. It has 18 speeds and doesn't require any tools for disassembly or stowage. Plus it weighs only 29 pounds, so it's easy to transport without taking up too much space onboard.