"J. Michael Milner" ) writes:
"Paul Keinanen" wrote in message
news
On Fri, 30 Jan 2004 02:05:19 -0000, (gudmundur)
wrote:

Is the 100khz Loran C signal useable while submerged? Do to it's
long wave nature, does it penetrate the surface to any depth beyond
a few feet?

Losses are about 10 dB/m at 100 kHz.

Paul


The U.S. uses VLH to "communicate with submerged submarines on at
frequencies of 3-30 kHz" (http://www.fas.org/nuke/guide/usa/c3i/vlf.htm).
The data rate is 50 baud but it must work - there are Trident ballistic
missile subs waiting for launch orders on the receiving end.
The depth and receiver characteristics are likely classified.


Depth of the boat doesn't matter. The antenna floats near the surface.