Danger for the Americans
Best keep this sort of thing away from the Yanks - some of them are quite possibly stupid enough to try this and then sue Google when it all ends in tears...
Google Maps seems to have got itself a sense of humour, if its recommended route from Stanford, California, to Stockholm is anything to go by. The entire journey is estimated at 7,826 miles (about 31 days 18 hours), but that calculation doesn't appear to take into account step 33: Google advises motorists to swim the Atlantic …
While it appears that Google can cross the Atlantic Ocean, it can't get across the Pacific Ocean. Attempts to go from the mainland to Hawaii are countered with a message: you can't get from here to there (or its equivalent). They should have a few more swimming portals around the world!