Continuous effort to improve Azipod energy efficiency. ABB, a power and automation technology group, has announced that recent modifications to its Azipod propulsion unit fr ame design have seen hydrodynamic efficiency improved by more than two percent. The modifications include a newly optimized Azipod fin shape and a new pod cap structure, called Xtail. The revised fin structure receives water flow from the propeller at a new, less acute angle, and its new curved design redirects the flow more efficiently.