reached an altitude of 3.3 meters, thus winning the Sikorsky Prize. Airships and balloons French inventors have built man-powered airships and balloons. Solar balloons and solar airships are new types of balloons and airships. Because lift is supplied through buoyancy, human power can be devoted to thrust. Watercraft Human-powered watercraft include prehistoric, historic and well-known traditional and sporting craft such as canoes, rowing boats and galleys. The term human-powered boat is often used for more modern craft using propellers and water wheels for propulsion. These can be more efficient than paddles or oars and especially allow the use of the leg muscles which are generally stronger than arm muscles, even for non-athletes. Competitive rowing boats use sliding seats to engage the legs for propulsion with an oar for this reason, but require considerable skill to use efficiently. In addition, there is little skill required for forward propulsion while looking forwards and craft such as pedalos are popular at resorts. Hydrofoils Hydrofoils have less water resistance at the highest speeds attainable by humans and are thus usually faster than displacement boats on short courses. The world speed record on water was set 27 October 1991 by MIT professor Mark Drela who pedalled a human-powered hydrofoil, "Decavitator", to 18.5 knots (21.3 mph)(9.53 meters/second) over a 100-meter course in Boston, Massachusetts, US. Submarines In 1989, the first human-powered International Submarine Race (ISR) was held in Florida with 17 craft. Since then nine more races have been held. The races themselves have been moved from the waters of Florida to the David Taylor Model Basin at the Carderock Division of the Naval Surface Warfare Center in Bethesda, Maryland, and are held biennially. At the 9th ISR in 2007 (in which 23 submarines participated) several new records were set: A single-person craft, Omer5 achieved a record speed of 8.035 knots breaking the Omer team's previous record of 7.19 knots set by Omer 4 in 2004. Also Omer 6 snatched up a record for non-propeller driven craft with a speed of 4.642 knots. See also Active mobility Adirondack guideboat Animal locomotion Bicycle and human powered vehicle museums, list of Carfree city Carrying on the head Erden Eruç Energy efficiency in transportation Jason Lewis Rowing Utility cycling References External links Human Powered Vehicle Records Human Powered Vehicle Challenge - American Society Of Mechanical Engineers Air Human Powered Aircraft Group - Virginia Tech Human Powered Helicopters - History,