ELLSWORTH — For a century or more, mariners navigating the rugged Maine coast have depended on sound signals installed at often remote lighthouses to help them avoid dangers in poor visibility. The mournful call of the fog horn is as much a part of the Downeast soundscape as the cry of the seagull.
Soon it will be up to the mariners themselves to turn on most of those sound signals.
Until relatively recently, most lighthouses in the United States were manned either by civilian keepers (often with their families) or by Coast Guard personnel. When Maine’s frequent fog reduced visibility, the lighthouse crew would activate the station’s fog horn as well as ensure that its light was in operation.
In local waters, most fog horns were diaphones, which sound low, powerful tones that can be heard at long distance and are produced by a moving piston powered by compressed air.
In the early 1960s, the Coast Guard replaced virtually all the diaphones with modern diaphragm horns that required smaller, less complex air compressors or could be powered electrically. At about the same time, the Coast Guard began automating lighthouses and eliminating the position of lighthouse keeper, who formerly switched on the fog signals. They were replaced by electronic fog detectors.
The automated detectors project a laser or photo beam out to sea. If fog is present, the beam reflects back to the source off the water droplets in the air and a sensor sends a signal to activate the foghorn.
This winter, the Coast Guard will start replacing existing fog detectors with a new Mariner Radio Activated Sound Signal (MRASS) system that will switch on a fog horn when it is triggered by a VHF radio signal on channel 83A.
“The MRASS devices will replace aging fog detectors that are prone to failure, expensive to maintain, and require specialized training to preserve,” said Capt. Michael Baroody, commander of Coast Guard Sector Northern New England. “We believe giving the mariner more control is an effective way to enhance the coastal aids-to-navigation system.”
According to Lt. David Bourbeau, of the Coast Guard’s Northern New England Sector Waterways Management Division, the current technology used for triggering fog horns is at least 30 to 40 years old and requires “a lot of battery power.” It also has a tendency to fail and, when it does, a fog signal will operate continuously until the problem is fixed.
That can be a real annoyance for neighbors of shore-based fog horns, and a threat to mariners who rely on the distinctive signal different fog horns produce to help fix their location on the water.
The new system will “increase operational reliability and decrease maintenance,” Bourbeau said.
The Coast Guard began switching over to the new system in 2009. Since then, MRASS devices have been installed at eight lighthouses in Maine and New Hampshire.
Over the next few months, MRASS units will be installed at 17 lighthouses in Maine. On the list are:
- Browns Head Light on Vinalhaven.
- Burnt Island Light in Boothbay Harbor.
- Cape Elizabeth Light at the entrance to Casco Bay.
- Dog Island Light in Eastport.
- Egg Rock Light in Frenchman Bay.
- Fort Point Light at the mouth of the Penobscot River in Stockton Springs.
- Goat Island Light on Cape Porpoise.
- Goose Rocks Light near North Haven.
- Heron Neck Light on Green’s Island near Vinalhaven.
- Marshall Point Light, near Port Clyde.
- Owls Head Light in Penobscot Bay.
- Portland Head Light, Cape Elizabeth.
- Sequin Island Light at the mouth of the Kennebec River.
- Spring Point Ledge Light in South Portland.
- Two Bush Island Light at the entrance to Penobscot Bay.
- West Quoddy Head Light in Eastport.
- Whitehead Light on Whitehead Island, Penobscot Bay.
The Coast Guard plans a major outreach effort to reach recreational boaters next spring, but Bourbeau believes that, with modern navigational equipment and prudence, the new system should not be a problem.
“The sound signal is only one tool out of many that should be used for safe navigation,” Bourbeau said.