HYDRAULIC CONTINUOUS RUNNING PUMP
Hydraulic Steering Systems
Raymarine Evolution pilots connect to hydraulic steering systems using a rugged hydraulic pump matched to the capacity of the hydraulic steering system.
If your system is hydraulic...
You'll need to find out the size (in cc) of the hydraulic cylinder ram(s) mounted to the rudder or inboard engined boats, or to the drive unit on outboard engined boats. Your steering system documentation will have this information.