This is particularly important while at dockside, when deck space is fully utilized. In addition, the kite rig is substantially manufactured away from the vessel. Downtime and retrofit costs are minimal. Further, a kite rig can be carried from one ship to another, as for varied testing, or as vessels change routes, or owners. Kites fly at higher altitudes than conventional rigs.
Wind velocities increase with altitude above the water.
This results in far higher apparent wind speeds at the kite than those experienced by the hull, and thus far more energy available than to a hull mounted rig . Calculations, and actual experience with kite rigged boats, indicate that these rigs may extract 4-10 times the energy of a conventional sail on these courses 4,8,9 . An analogy may be seen in a modern windmill's moving blades. The energy extracted from the wind is related to the blade's swept area over time, not to the blade's actual surface area. Very large kites are feasible.