deck_holder_width = sonar_holder_width - deck_depth;
deck_holder_height = sonar_holder_depth * 2 + deck_depth;
linear_extrude(height = deck_holder_width) {
deck_holder_width = sonar_holder_width - deck_depth;
deck_holder_height = sonar_holder_depth * 2 + deck_depth;
linear_extrude(height = deck_holder_width) {