SeaSense 36" x 36" SOS Distress Flag Go to amazon.com Related posts How to find the best boating visual distress signal for 2019? FeatureMeets U.S.C.G. Requirements DescriptionOur SeaSense Distress (SOS) Flag measures 36 x 36-inches, and has a black square and circle printed on an international orange flag. The flag is a USCG-approved daytime distress signal.