@RealGene @Badgardener @spocko Thanks! There is a long and far from exhaustive list of human powered aircrafts on Wikipedia. My favorites among the unlisted are the Zeppy (1, 2 and 3) which someone brave enough may be able to sail across open water, using a device called a "chien de mer" acting as a centerboard newatlas.com/zeppy3-sail-ballo