No, its no problem getting out. Radar and radio reception is not a
requirement to be IFR. You simply call the FSS and they will relay a
clearance to you from ATC. Your clearance will be valid upon enter
class E airspace (no need for clearance in class G). So I would
typically file to a nearby VOR (or all the way home). They will
provide you a clearance void time, clearance limit,etc, and you
launch. Its not difficult. Once you are on top and in radio range you
can simply cancel the IFR.

-Robert, CFII

About 4 miles offshore of Shelter Cove, there's a large area of class
G airspace extending upwards to 14,500, so if it's just fog, you might
not even need a clearance.

I live in Humboldt, and visit the Cove every once in a while. On a
clear day, it's absolutely gorgeous. Most everything is closed on
weekdays, but on weekends there are several places to get some pretty
good fish and chips. The beach is rocky, but very nice to walk along,
and you can usually see seals, sea lions, and the occasional whale.
the Cove is also one end of the King Range trail, a scenic coastal
route for hikers and campers. A nice fly-in destination.