Sometimes I have this problem too, but you may be able to see where someone dragged a trl out and the tires left tracks you can use to follow back to the dock. Seams in the concrete work too. As for the blind side backing, had to do one the other day with no room out front. I had the customer's day driver move his bobtail out on my right and took my time, getting out several times checking where I was. Dock man said I made it look easy, that made my day.

 

This time of year, watch the tracks in the snow.