aaaaa Radio Waves Radio Waves The assignment: Depart Leith, Scotland, proceed east through the Firth of Forth to the North Sea, thence north past the Shetlands, the Orkneys, even well past the Faeroes, send one final radio message announcing that we were diving, submerge, penetrate the shield of destroyers, airplanes, and helicopters, and simulate sinking the aircraft carrier, HMS Ark Royal. Simple. We had done it dozens of times. Everything eventually went just as planned, except . . . In 1970, when this was taking place, we still had no satellite communication capability. We used old-fashioned, quirky HF (high frequency) ship-shore radio circuits. HF radio is quite vulnerable to weather conditions. This day we had the worst problem that I ever saw with HF radio propagation. Our first choice was to send the message to the U.S. Naval Communications Station (NavCommSta) in Northern Ireland. That was a distance of only 200 miles or so. We never managed to communicate any form of information to or from Ireland. We then tried other NavCommStas, progressively farther away. We could at least get a call sign through, but nothing else. We were getting through to Washington, DC and Balboa, in the Panama Canal Zone, better than we were communicating with Londonderry, but neither of them could read us clearly enough to give us a receipt for our message. We tried others, with no luck. We almost got it through to NavCommSta, Morocco, but at the last minute they declined to accept the message with so many garbles in it. Of course we checked out our equipment. The radio receivers and transmitters were performing exactly to specification. The antenna connections were dry and tight, as good as any we had ever seen. The problem was not with our boat. Atmospheric conditions were preventing any HF communication with our neighbors. We tried to send the message to some of the ships in the exercise, but they could not hear us on HF. They did send an airplane over to yell at us on the UHF radio, telling us to send the HF message, already. UHF equipment used voice, and HF equipment used teletypes, so our strained reply did not count as sending a diving message. Finally, in desperation, one of the junior radiomen tried something. He had just transferred to our boat from NavCommSta, Adak, Alaska, and he remembered some radio frequencies for the Pacific Ocean. These radio frequencies were not listed in our Atlantic Fleet publications. This young, new radioman tried all the circuits to Adak with no luck. Then, astonishingly, he got through to NavCommSta, Guam, loud, clear, and error-free. The problem was, while we could talk to Guam, we couldn't, as it were, tell them anything. (Exact details classified.) But we knew that this was our only chance, so we pulled out some stuff from way in the back of the safe, stuff that we had been given for exactly this type of desperate situation. We spent some time around the wardroom table with paper and pencil, and we came up with something that it was legal to tell Guam. Then we submerged, motored right through a huge protective screen put up by combined forces of six NATO countries, and took a photograph of the Ark Royal through our periscope, from a few yards off her starboard beam.