Has it even been done before? Searching the internet only finds huge manned solar boats.
Swimming around the earth with solar power should be much easier than flying as one doesnt have to worry about the night (really? see below). Another advantage is, that nations tend to try and protect their airspace whereas swimming through international waters should be fine.
The idea is, to have an autonomous robotic vessel, powered by photovoltaic means and two underwater propellers and doing navigation with gps. While shipping around the world, it would be great to have photos from all the exotic coastlines the robot approached. Image analysis could also be used to avoid getting too close to potential obstacles in the water.
There would be two possible routes. Either hoping to get through panama and suez canal together with other ships (and try not to get stuck by the canal sides) or swimming around cape horn and cape of good hope.
Having an uplink to the vessel would be great and certainly very useful but there doesnt seem to be any solution for satellite navigation that doesnt cost a fortune, isnt a huge installation and works around all the globe? Such an uplink would make lots of things much easier and would avoid loosing the robot.
A quick mockup of how such a robot could look like:
- What about corrosion of the propeller/motors due to salt water?
- What about extreme temperatures? will the electronics cope with that?
- Could something cover the solar panels? Ice? Dirt?
- What about the Night? Build in batteries to keep it powered? Would the robot drift away?
- Are there currents too strong for the robot to overcome?
- Will motors wear out?
- Will someone find it and take it away?
- Is it legal?
- Go through suez/panama canal? How to avoid getting stuck there?
- Could it strand on a coast or riverside being stuck in plants or rocks?
- Enough power from solar cells? How large do they have to be?
Apparently people are already into this: