These guys used a pedal-powered, two-man boat to circumnavigate the world.
Expedition 360 - Pedal Boat Moksha
Maybe you could do it with paddles. I know a guy who paddled a kayak from California to Hawaii, and there have been a couple of Atlantic kayak crossings (though those were quite sail-dependent). But those were kayaks, a whole different level of risk/exposure than the craft these two guys used. Not that they had a pleasure cruise.