BOTH INTERNATIONAL & INLAND You are underway in fog when you hear the rapid ringing of a bell for five seconds followed by the sounding of a gong for five seconds. This signal indicates a vessel __________.

Under Inland Navigation Rules, for the condition where 'You are underway in fog when you hear the rapid ringing of a bell for five seconds followed by the sounding of a gong for five seconds. This signal indicates a vessel', the correct requirement is: 'more than 100 meters in length, at anchor'. This standard ensures clear navigational intent and collision avoidance.