Posted by David Bamford on March 27, 2009 at 19:25:31 user David.
In Reply to: signalling, was: Re: burghers of Carlisle posted by Ed Kiser on March 27, 2009 at 17:27:08:
Regarding the origin of the morse "U" to signify "You are standing into dnager", it is a simple transfer of the signal flags which you referred to earlier [I request a pilot, etc]. These are primarily letter and number flags, and the flag for the letter "U" has a secondary meaning of "You are standing into danger" [ie, heading for rocks or a shoal]. The message referred to earlier requesting a pilot is the single letter "G". The combination of two letters enables a whole host of complex signals to be sent quickly. These are detailed in the small volume "Brown's Signalling", by W.K. Stewart. [Brown was the publisher.]
David.