When on a road trip, I usually monitor the 2m FM calling frequency, 146.52 MHz. For the most part, that frequency is pretty quiet but sometimes a fellow traveler, camper, SOTA activator or random ham shows up on frequency. I don’t usually bother with tuning into local repeaters as that requires frequent adjustment of the radio while cruising down the highway.
Our RV has an Icom IC-2730A transceiver that covers the 2m and 70 cm bands. This radio has two receivers, so one receiver is set to 146.52 and other one is set to “something else.” Sometimes, I’ll go ahead and put one of the local repeaters in the other receiver, especially if we are going to hang out in one location for a while.
When driving near coastal areas, I often put the second receiver on the VHF Marine Channel 16 (156.80 MHz). This is the International Hailing and Distress Frequency for marine radio. You will hear boats calling each other on this channel, then switching to another working channel. It is also common to hear the U.S. Coast Guard come on the air with an announcement. (The USCG may say switch to Channel 22 to hear the announcement.)
Some other useful marine frequencies:
Channel 22 157.100 MHz Coast Guard Liason Channel
Channel 68 156.425 MHz Non-Commercial Working Channel
The complete list of VHF Marine frequencies are available here:
Just another frequency to listen to when on the road.
73 Bob K0NR