Attached Link: http://www.btinternet.com/~k.trethewey/ChannelCrossing.htm

I think that Musicat pounced upon it. However, being curious about British lighthouses, I did a spot of research anyway. Caligula may have been a monster, but his engineers put up a solid building. This is a decent site discussing all the lighthouses in the Dover area including their light signals. :) Carolly