I know lighthouses each have their own distinctive flash sequence but I don't know if the same applies to foghorn noises. I tried googling but the only thing I could discover is that the foghorn at Mumbles lighthouse (installed in 1908) is known as Jasper's baby. I have no idea why.
The other interesting thing I found out is that all lighthouses are controlled from a central point in Harwich. (Central to what I'm not sure.) Coastguards at St. Ann's in Pembrokeshire were recently contacted by Harwich who asked, 'Where has your lighthouse gone?' Apparently it had disappeared from their screens. According to the St. Ann's website, 'the culprit turned out to be one of the local cows who had leant up against the control box in the adjacent field and disconnected all the electrics!'
High tech is no match for a lazy Freisian.