A foghorn with a red horn and white canister

Check out the U.S. Coast Guard’s navigation rule regarding sound signals in restricted visibility.

What you don’t hear can hurt you

Sounds of safety

Sooner or later, most of us encounter fog while on the water, and understanding sound signals could help you avoid a collision.

While a GPS and chart plotter will tell you where you are, they cannot tell you what is around you. Radar, however, can be a great help if you know how to interpret the blips on the screen. Regardless of what equipment you have, the law requires sound signals, and you will be much safer knowing the basics.

Years ago, when only large boats had radar, I took a squadron cruise to Nantucket Island, Mass. In those days, all we had was a radio direction finder, which required you to interpret Morse code signals from ground stations in strategic locations. Fortunately, I also could rely on my Piloting and Advanced Piloting knowledge.

The squadron fleet left Martha’s Vineyard on a reasonably clear day. A couple of hours out of Vineyard Haven, a fog rolled in and reduced visibility to 100 feet or less. However, we all knew fog signals.

My son, Russ, took the helm, and I positioned myself in front of the mast, away from the engine noise, to better hear sound signals and scan the water ahead for other boats’ wakes. In addition to my canister horn, I also had a horn that used lung pressure as I did not know how long the canister horn would operate.

I sounded one long blast, and a powerboat about a quarter-mile starboard sounded another. Following my signal, the squadron sailboats to my port side also sounded signals. We continued signaling for three hours.

When my dead reckoning track said we should be off Nantucket Inlet, a hole in the fog revealed the powerboat that had been paralleling our course. The boat had a radar arm in motion, and I asked the captain if he could see the inlet. He said there was either a buoy or boat about four miles ahead. I realized that he didn’t know what he was looking at, so we turned to starboard.

About a half-mile from Nantucket, the fog lifted, and we saw the inlet. Thanks to Advanced Piloting, my dead reckoning had led us right to it.

As we approached the breakwater, the powerboat captain stuck his head out of the side of his boat and thanked me. I wondered what he was thanking me for, and after we were tied at the dock, I walked over to chat with him.

The captain said he did not know how to use the radar and was following us. “You sailboat guys always know how to navigate,” he said. We stayed with him a bit longer and taught him how to read the radar.

Inexperienced boaters can learn a lot from the captain’s experience. A good knowledge of paper charts and sound signals is essential, especially if your electronics knowledge is limited or your equipment fails at sea.