A unique and variable displacement feature on the helm that allows number of steering wheel turns to be adjusted by helmsman to his preference within a pre-determined range. Internals of pump have been redesigned to eliminate potential air traps and to enhance air removal. Meet ABS, Lloyds and Det Norske Veritas specifications. Systems are not pressured by air, eliminating concerns about air leakage or pressure drops. Separate reservoir is not required as each helm contains its own reservoir. Built-in pressure relief valves in helm protect the system from effects of thermal expansion.