Bright, white soundless orb with no trajecory nor trail of flames

A white circle appeared off starboard bow,resembling a ship's running light.  Distance at sea from a sailboat at night is imperceptible,so fearing collision with a larger ship, I "came off the wind" to slow speed.  The orb,not as large as the moon would appear, shot dead across the dimly lit horizon, toward the starboard-quarter in a split second.  There was no trajectory nor trail of flames like a rocket.  It simply passed at an incredible speed. No one to whom I've spoken had any explanation for this observation.
At the time, my family, two crew members & I were enroute to Hawaii from Newport Beach, CA. It was my shift at the helm, so I was the only person top-side.  Would really like to know what Type of sighting I witnessed.
No sound was emitted from the bright, white object.
Date in October 1968 is approximate.  PD