I've been warned of squall lines at least twice by keeping 16 in the scan pattern and it's saved me from getting caught with my pants down.
Years and years ago, before there were shoulder belts in cars, and the push to encourage people to wear their seat belts was just winding up, I was an on again, off again seat belt user. As it happened I one day was involved in a collision where I probably would've been seriously injured had I not been wearing that seat belt. That turned me into a conscientious seat belt wearer.
Likewise, I used to be kind of lax about monitoring channel 16. I knew I should, both for our safety and the safety of others, but I wasn't real consistent about it. Then, season-before-last, luck struck again. This happened to be a day when I'd remembered, and so we'd been monitoring channel 16 all day. At one point, literally "out of the blue," a gale warning was issued by the closest Coast Guard station, based on a report from a nearby yacht club's instrumentation and observations. We had just
enough time to get the iron genny cranked up, her nose pointed into the wind, and the sails down and minimally secured when it caught up with us. Had we not received that warning when we did, we could have been in quite serious trouble.
The wind was loudly whistling thru the rigging. We can normally easily do over 6 kts on the iron genny. We couldn't even make 3. One sailboat south of us was in real trouble and calling for CG assistance. Multiple powerboats were in trouble. A slip neighbour returned with their headsail furling system fouled and the sail badly torn.
I'm a lot
more conscientious about monitoring channel 16 ever since that.