Andrew, VE8AE wrote:
"To operate from a fjord like area on the bottom would really kill your
signal would it not?"

Assumining Andrew does not mean the bottom of the water, it depends on
the width, length, and depth of the crevice.

I once rafted down the Colorado River between the walls of the Grand
Canyon. It is between 4 and 13 miles wide at its brim. It is from 4000
to 5,500 ft. deep and over 200 miles long with lots of twists and turns.

Medium Wave reception was near zero, but shortwave reception was just
fine in most places along the canyon floor.

Best regards, Richard Harrison, KB5WZI