A fluid level sensor for a fluid tank of a marine vessel is provided. The sensor includes a sensor mount and further includes a circuit housing that is pivotally connected to the mount to pivot about a predetermined pivot axis. A float assembly is configured to supply an actuating angle substantially impervious to fluid tank tilt and/or fluid splash at least along an axis generally perpendicular to the pivot axis. A circuit in the circuit housing is responsive to the actuating angle from the float assembly to provide an output signal indicative of the fluid level in the tank.