Does the length of a LORAN metal whip matter much? I recall a time when I
found I didn't even have an antenna on my LORAN (years ago); just a coil of
coax under the console, and it worked fine. So, can I stick just about any
whip on the coupler and get good results? Or, is there some reasonant
length that is needed?

I'm putting a LORAN in my 18' cc, and want to use a short metal whip on the
coupler, if that'll work OK.