Aim for the hole in the bridge.
The canal in following the contours, moves over the place, seemingly a times to resverse in direction. You can see boats moving over the wall, but be unable to tell if it is going towards you or away,
distorting all sence of direction. When travelling towards East Marston from Gargrave there is a transmition tower visible in front,
a common qustions is: Which side of that tower are we going to go?