Yes this is true. "In general, any vessel equipped with a VHF marine radiotelephone (whether voluntarily or required to) must maintain a watch on channel 16 (1

Yes this is true. "In general, any vessel equipped with a VHF marine radiotelephone (whether voluntarily or required to) must maintain a watch on channel 16 (156.800 MHz) whenever the radiotelephone is not being used to communicate." The only exception is if in a Vessel Traffic Service (VTS) area, then must be monitoring the VTS channel. (But even cheap handhelds VHFs will monitor two channels at once) https://www.navcen.uscg.gov/radio-watchkeeping-regulations https://www.navcen.uscg.gov/radio-watchkeeping-regulations Article says this was in Farragut Bay which is not a VTS area. So, yes, every boat around was required to be monitoring VHF channel 16.