MOVING THROUGH THE Murk &Fog

Onne van der Wal remembers what it was like to navigate through the soup back in the 1970s off the coast of his native South Africa.

“We were using a little book by Mary Blewitt about coastal navigation, and it was all about radio direction finders,” Onne recalls. “You’d leave Cape Town, which was a certain radio frequency, and then go up the coast 60 miles to the next station, Robben Island, where Nelson Mandela was imprisoned. The next one was Dassen Island. There was a lot of fog there. You tuned in a radio frequency and when it was at its strongest, that was the bearing. You’d triangulate it against another station’s frequency and put it on a chart. Then you’d say to the boat owner, ‘This is where I think we are.’”

There was no Loran in South Africa and this was