A one-hour, 43-minute flight between a hospital on the Caribbean island of St. Croix and a testing facility on the neighboring island of St. Thomas probably set a record for hydrogen-powered multi-rotor, over-water drone flight. The flight delivered live bacteria samples from a hospital on the Caribbean island of St. Croix to a testing facility on the neighboring island of St. Thomas. The demonstration was carried out by Guinn Partners and associated organizations. Most such medical deliveries are usually over land and within urban areas. Fixed-wing drones flying with Zipline in Rwanda deliver clinical samples and blood 80 kilometers (49.6 miles) each way out and return. The Doosan Mobility Innovations (DMI) DS-30 drone is a large machine able to carry a 10.8 liter, 4.3 kilogram (9.46 pound) compressed hydrogen container – good enough for two hours endurance. There was 30 minutes’ supply left in the tank when the drone landed on St. Croix. The machine can carry up to a …