I recently ran across the PlanetSolar project to sail the boat Turanor around the world. 51 days into the voyage they have crossed the Atlantic, leaving from Monaco and are currently in the Caribbean near the island of St. Maarten. The expedition crossed the Atlantic in 25 days.
The Turanor is a 31 meter catamaran with a 23 meter beam including the solar "flaps" weighing 95 tons, she carries 537 square meters of solar panel that offer 18.8% efficiency. It's a pretty amazing undertaking, circumnavigating the world on solar power, stopping in major ports along the way to spread the word on solar power and sustainable options. Their two major stopovers in the US will be in Miami and San Francisco.
You can check out the project at
http://www.planetsolar.org/index.en.php. The site offers a lot of information, some great pictures, videos and interactive tracking applications. It's well done and worth a visit.