DivingBiker and I did that, too!
We, along with my DH, did a lap around Rosaryville State Park on the mountainbikes. ~10 miles of sweet, rolling singletrack. It was a hoot!
Then...a friend let us borrow his sailboat - a 16' Bullseye - and we went for a sail along the South River near Annapolis. I don't think DB was quite prepared for how loooong it took to get a boat ready to sail (especially when it's not yours and you only did it once before and um...don't quite remember all the steps! Oh, and then have to put it away...just so...so the owner doesn't think you're an irresponsible jerk and never let you use the boat again!
). The wind was light and variable, but it moved us. The next step, tho', is to get some pillows for the bench seats. The teak sure looks pretty, but it's a bear to sit on for a 2 hour sail!!!
2007 Seven ID8 - Bontrager InForm
2003 Klein Palomino - Terry Firefly (?)
2010 Seven Cafe Racer - Bontrager InForm
2008 Cervelo P2C - Adamo Prologue Saddle