Years ago we fitted a strobe light to the masthead of Intermezzo, to serve as a warning light to make sure we were seen by shipping. Later we heard this was not such a good idea, because it was difficult to determine distance off when viewing strobe lights.
As it turns out, we never used the strobe, and never fit another on future boats.
From time to time we would see fishing boats with strobes. They were always a long ways off and we could see the fish boat targets on radar to check distance.
Fast forward to several weeks ago. We were having a lovely nighttime passage down the coast of Washington. Off the mouth of the Columbia River, 40 miles from land, we picked up a strobe light. It appeared to be several miles off our starboard bow, but we could not pick up the target on the radar. This was unusual, as there was not much sea running. With a 12kW radar and 2 meter wide antenna, we rarely miss targets.
We picked up our binoculars to check the strobe, and were startled to see the outline of a small salmon troller quite close – maybe 150 feet (45 m) distant!
We can now attest to the fact that strobes are not a good idea. If you really want to be seen, use a bright masthead light, and then turn on your deck lights to make sure the approaching vessel does not miss you.