[maillemaker]

So during the war, subs got nailed whenever they used their radios, due to direction finding equipment.

I'm surprised that they did not event a throw-away floating radio transmitter that they could put their message in, throw overboard, and then, when they were far away, it would transmit the message and then sink.

Or, better yet, set up a floating transmitter and anchor it somewhere (or let it drift), while it transmitted from time to time, and then lie in wait and nail whoever steamed along to try and "sink" the "sub". In other words, use the transmitter as bait.

Steve