As applied to fire fighting: The ability of the operator to manipulate the controls from a driving/riding position without excessive movement away from the seat back or without excessive loss of eye contact with the roadway. NFPA 1901, 1999 ed. As applied to marine vessels: In marine fire fighting vessels, the ability to operate controls without excessive movement from a fixed position such as a seat or safety harness. NFPA 1925, 2004 ed