Whilst anchoring vessel; unable to proceed due to thick fog, on running into the anchorage an echo was seen on the 3M range on the radar. The echo was seen to be tracking clear of the vessel, but would pass close. We had a patrol boat ahead of us and this was dispatched to see what the echo was and advise them of our intention to anchor. The patrol boat found the echo to be a yacht. It had a chart plotter, but no radar. The person in charge of the yacht was happy that he knew where he was in the fog and therefore OK. He was happy crossing a busy waterway/port approach. He obviously thought that everyone was going to keep out of his way. The worry is how many yachtsmen have this attitude?
Restricted visibility may be encountered at any stage of a voyage and all mariners must be prepared to take appropriate measures based on their particular circumstances and their assessment of the risks involved.
It is not clear from the details of this report, but there would be scope to criticise an individual who chose to leave port under these conditions, in this location, without radar.
The Maritime Advisory Board believes Rule 19 is most effective where both vessels are radar equipped. Radar equipped craft need to bear in mind that other vessels may not be; particularly in areas frequented by leisure sailors, and navigate accordingly.
Sound signals should be used.