A line across the hillside

The volunteers were marking a new walking route with permission from the landowner. From below, the next post seemed close. On reaching it, we discovered that the slope concealed a deep drainage channel. The older gate shown on our map had been removed. Mist then covered the landmark we had been using to judge direction. The marker tape would not stick to the wet posts, and the roll became tangled as we tried to keep it out of the mud. We stopped marking until the route could be checked properly.

Describe the difficulties encountered while marking the route. You may support your points with brief quotations.