This is a hoot. Not exactly a cruising boat, but maybe something to give you a little exercise – or even take you ashore – when you anchor out. The 44-pound Manta5 is a hydrofoil water bike that lets you ride on the water. The two carbon fiber hydrofoils create lift (think of the America’s Cup boats in Bermuda), while a 400-watt motor provides enough power to reach a top speed of 12-mph. The battery lasts for about an hour, or you can just keep pedaling manually forever. The whole thing folds up to fit in a car trunk, or…