Some days ago we made an overnight passage from Nova Scotia to Newfoundland. At about 2:00 am, Phyllis picked up a slow-moving target at about 2.5 miles on radar.
Despite it being a dark and clear night, with a tiny sliver of waning moon low in the sky, we could see no lights, even through our high-quality Steiner binoculars, and they suck light.
Finally, when the target was just 1.5 miles on the beam, and against the blackness of the land, we were able to just barely discern a very faint white glow that we finally recognized as a steaming light reflecting off the target's headsail—indicating a sailboat motorsailing—but during the whole encounter we never saw red or green sidelights, and we only saw said glow because the radar was giving us the exact bearing to direct the Steiners on.
I gave them a call on VHF and was immediately answered with the information that they were indeed a sailboat motorsailing.
And then, when the range had closed to about a mile, an AIS target came up on our plotter for the very first time. Said target only showed the other boat's name for a moment or two and then reverted to an MMSI number before blinking out completely at about 1.5 miles.
I took two important lessons away from this encounter: