We were sailing our yacht in fresh conditions (force 4 to 5), and approaching a harbour and marina where we intended to stop for the night. The sea state was moderate, visibility good. We had noted from the (current UKHO) charts the presence of two fish farms on the approach and had taken care to keep well clear of the charted positions of both of these.
We had identified the lights at the harbour entrance and were heading towards these when we noticed red and blue flashing lights amongst the background of yellow street lights on the shore. This gave every appearance of being an emergency vehicle on shore.
We discussed what this was and continued to watch these lights whilst primarily concentrating on our target, the entrance to the harbour. We were then both surprised and shocked to find the blue and red flashing lights very close alongside our boat – on top of a small light-coloured buoy. No lights appear around this fish farm on the current chart, of any colour. We were lucky to not hit this, passing it some 2 metres away. We then safely entered harbour and berthed our boat.
The next morning we asked the Marina Manager about this light and he knew nothing about it. He telephoned the fish farm manager, who confirmed that all his buoys around the fish farm were lit by yellow flashing lights – as would reasonably be expected; even though these were not charted. There were indeed some (rather weak) yellow flashing lights elsewhere around this fish farm which we had also seen on our approach the night before.
I was still concerned about this and retraced our track as we left port later that day. We found the buoy approximately 5 ca due north of the entrance, exactly on our inbound course as indicated on the GPS inbound track.
I called the Coastguard to report this incident and was informed by them that red and blue flashing lights are locally agreed indications of a fish farm. I asked if this was notified to mariners anywhere and was told that, no, it was just a local authority matter (!). I asked the CG to note my concern that the uncharted and un-notified light had caused considerable confusion and also that I considered this most hazardous, which they agreed to do.
We contacted the Local Aids to Navigation Inspector of the General Lighthouse Authority for the area. He was aware of the issue and had instructed the fish farm to change the lights. These would soon be changed to flashing yellow, as recommended by the International Association of Marine Aids to Navigation and Lighthouse Authorities (IALA).
Intervening to correct a hazardous situation is a key step in improving safety. By following up his concerns regarding the incorrectly lit buoys, the yachtsman helped to instigate corrective action.