I don't know what the CG uses for VHF receivers, but when I was a PNW fisherman, I often heard them talking to boats in distress as much as 200 miles out. If you're in an area with fishermen or crabbers, they are monitoring the emergency channels. And where necessary can relay messages or help.
Off the West Coast fog is common above SF. I remember a call from a yacht that was lost in the fog and circling the #1 buoy at Fort Bragg. When the CG cutter got out to the buoy, no boat. They got a radio direction on his signal and found him 20+ miles south going around a different #1 buoy. The rest of the story is it was a busy day. A 2nd yacht was having some distress and about 20 miles straight out. The CG would have gone there 1st, but assumed the #1 problem yacht was on their way. That led them 20 miles out of the way. As it turned out a fishing vessel helped the 2nd yacht. That particular day I was towing another boat that lost his prop.
From someone that has spent a life on the ocean, and hearing dozens of small boat distress calls, the CG gets way too many unnecessary calls from people that are unprepared.