Yacht Length

M650 (mk2) 16 kg 23ft 7m
M790 (mk2) 17 kg 31ft 9.5m
M950 (mk2) 18 kg 40ft 12m
M1070 (mk2) 19 kg 50ft 15m

Force available @ power arm line attachment point.
@ Boat speed

3 knots 6 knots
300 Newtons 1600 N
350 N 1900 N
400 N 2200 N
450 N 2400 N
Power increases with the square of boat speed. Model numbers (650, 790, 950 and 1070) refer to the height in millimeters from the water line to the centre of the mounting boss, when the vessel is not underway. This measurement allows for 200mm of stern wave for the Neptune rudder to be at its optimum level in the water when underway. To convert these measurements to inches, divide by 25.4, i.e. the M650 requires a measurement of 25.6 inches.
A standard Neptune unit will be supplied with:-
Colour coded rudder and airfoil
  1. Course adjusting crank with the option of either the short model or the flexible, extension crank (500mm long)
  2. Operating, service and installation instructions