Of places I would want to take a cruise, Titan (the largest of Saturn's moons) would probably not* be at the top of my list. It's nearly 300 degrees below zero most of the time, the atmosphere is unbreathable, and swimming in liquid ethane and methane sounds unpleasant. None of that is a problem, though, for this little robotic paddleboat.
The Titan Lake In-situ Sampling Propelled Explorer, or TALISE (it's European, go figure), is a cute autonomous explorer boat that's being proposed for a mission to Titan. If it's selected as a mission, TALISE would land in the moon's largest body of water and then slowly paddle its way towards the nearest beach (or whatever passes for a beach on Titan) while taking scientific measurements the whole way. The mission would last between six months and a year, and would be the first time we've ever managed to land a boat on another planetary body.
While one design for TALISE comes with paddles, other options include water wheels or water screws, although neither of those are quite as charming:
This is all still at the "Phase 0" stage, which is equivalent to having a really cool idea, but not a heck of a lot more. The TALISE concept was presented yesterday to the European Planetary Science Congress, and if it's popular enough, the next steps will be a feasibility study, a technical proposal, and (if we're lucky) an actual mission at some point in the future.
*Who am I kidding, it would totally be at the top of my list.