Have you ever read "Flying South" by Barbara Cushman Rowell? There's an
amazing story in there about flying up along the coast of Brazil at
100' MSL in the fog, a VFR pilot, trying to keep the coastline in sight
and find a place to land before she got lost in the fog.

this is an amazing book actually. It doesn't solely focus on flying
though. At the time they were flying "visually" but she and her
passenger/friend were both IFR pilots. I don't re-call the 100' MSL
though. I remember the next day or two when they took off again, in
the next harbor over, there were power lines up to 1000' or so.

Sadly, her and her husband (famous photographer Galen Rowell) died
in a Commander aircraft going from OAK to BIS a couple of years ago.

Gerald