Need something interesting to do, and a reasonably safe adventure? The Great Loop is just the thing. It's 5500-7000 miles (depending on your route), so it takes a while depending on your pace.
It's the boating version of the Appalachian Trail.
To make it longer and more adventurous, some Loopers skip the Hudson River and go around the Gaspe Peninsula and down the length of the St. Lawrence.
First, you have to find the right looper boat.
Here's the American Great Loop Cruiser's Association site.
Of course, for car trippers, there is The Great American Road Trip. Everybody probably ought to do it once. I only got as far as Denver and a bit of New Mexico when it was time to turn around and get back to school. Every 100 miles, my pal and I would trade off running a mile or two along the road to stay sane (difficult to do on an airplane trip, unfortunately). Good essay on the topic at Smithsonian.
I'm sure we have plenty of readers who have done the latter, but do we have any Looper readers?