A new screw propeller with higher efficiency than a conventional state-of-the-art propeller. Whereas traditional ship propellers have blades modeled on the basis of helical surfaces, the KAPPEL propeller has modified blade tips smoothly curved to the suction side of the blade. A first full-scale KAPPEL propeller was manufactured for the 35,000dwt product carrier MT NORDAMERIKA. It was tested at sea immediately after tests with the conventional propeller originally designed for the ship. The results confirmed the model test predictions that the improvement in efficiency of 4% aimed at was achieved. Furthermore, the pressure pulse level was slightly lower with the KAPPEL propeller than with the state-of-the-art comparator propeller.