7. Hornblower Hybrid

Late last year, Hornblower Cruises & Events introduced the Hornblower Hybrid, which is powered by hydrogen fuel cells, solar panels, and wind turbines. The 600-passenger yacht, which has indoor and outdoor decks, comes outfitted with LED lights, complimentary Wi-Fi, and on-board touch-screen tablets.
Photo: Courtesy of Hornblower Cruises & Events