Danielle Doyle

The Sirius Signal team worked with USCG representatives to conduct studies researching the best colors and sequences to use when summoning help in a maritime emergency. Their findings resulted in new carriage requirements and regulations.

San Diego, CA — After 100 years, the marine SOS visual distress signal will change colors in the United States. On December 21, 2018, the USCG issued a Policy Letter accepting red-orange/cyan as official colors to be used in maritime electronic visual distress signal devices (eVDSDs). This is a result of a multi-year project to evaluate the effectiveness of existing distress signals – including the “S.O.S.” pattern – when used to alert others visually, of an emergency on the water.

“[USCG] recognized that pyrotechnic distress signals are old technology. Existing distress signal requirements and electric distress signal specifications need to be revised to match the advanced technology and performance capabilities of newer devices,” said Martin Jackson, a staff engineer with CG-ENG-4, in an article released on the Coast Guard blog in 2018.

An initial field study report was issued in Long Island Sound. To assist with the research, Sirius Signal funded an additional 2017 field study in the San Diego Bay. Dr. Anita Rothbloom from the Coast Guard Research and Development Center was in attendance to observe multiple colors and distress sequences that were being tested. Sirius Signal executive members were also asked to share findings from their focus groups of the C-1001 SOS Distress Light Flare Beacon.

Their research confirmed that the SOS signal is still being taught and that a red-orange/cyan light flashing the SOS pattern is most recognizable while on the water.

“We are passionate about helping the maritime industry evolve and are honored to have been involved in the USCG regulations testing process. We are setting a precedent with how technology can lead the charge when it comes to new carriage requirements,” said Anthony Covelli, CEO of Sirius Signal.

“We were able to save the ‘SOS’ signal and increase the effectiveness of eVDSDs in the process.”

“SOS” became the universal standard used to summon help (most frequently in maritime settings) on July 1, 1908. It was first used less than a year later by Cunard liner SS Slavonia off the coast of Portugal and has been used by mariners in distress since. Adding new color requirements are one of the few updates that have been made to the SOS signal in the United States in over one hundred years, and other countries are likely to adopt the convention.

“The resulting standard on electronic visual distress signal devices (eVDSDs), published June 21, 2018, by the Radio Technical Commission for Maritime Services (RTCM), “opens the door to permit a new type of LED-based visual distress signal with advanced technology that is both safer for the user and environmentally friendly,” Jackson said.

Manufacturers should plan according to the most recent USCG policy letter. Sirius Signal will be reviewing new platforms later this year which will satisfy all USCG requirements for nighttime distress devices.

San Diego based Sirius Signal produces USCG approved day and nighttime distress devices with a focus on safety, technology, effectiveness and sustainability. To learn more about purchasing Sirius Signal devices or to request more information about our field studies, visit us at or call 888.526.0005. More information about this release? Contact

About Sirius Signal LLC

San Diego-based Sirius Signal produces USCG-approved distress devices with a focus on safety, technology, effectiveness, and sustainability. To learn more about purchasing Sirius Signal devices or to request more information about our products, visit us at or call 888.526.0005. More information about this release? Contact

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Danielle Doyle


Jeff Flake, Sen., “S.140 — 115th Congress (2017-2018),”, December 04, 2018. Accessed January 21, 2019,

Loretta Haring, “Research, Development, Test and Evaluation Spotlight: Alternatives to Pyrotechnic Distress Signals,” Coast Guard Compass, July 10, 2018. Accessed January 22, 2019,

Rohrer, Finlo. “Save Our SOS.” BBC News. June 13, 2008. Accessed January 22, 2019.

“The Origins of SOS and Mayday.” OxfordWords Blog. January 10, 2017. Accessed January 22, 2019.