The slight slope and man-made obstacles disrupted the charge.
On sectional charts, man-made obstacles less than 200 feet in height may not be shown.
The trail also includes natural and man-made obstacles such as rocks, wooden bridges, logs and stairsteps.
After several hours, those man-made obstacles were completely cleared and the Jin fleet continued advancing.
Each race has around 12 man-made and natural obstacles that runners must overcome.
Bike trials - Slow negotiation of man-made and natural obstacles where setting a foot down constitutes a penalty.
But man-made obstacles had never stopped him before.
Just 20 feet from the docks is a street course positioned with man-made obstacles including rails, box jumps and halfpipes.
Avoid trees, stumps, rocks, branches or "man-made obstacles," it warns.
Bike trials is a sport where riders navigate natural and man-made obstacles without putting down their foot, or "dabbing".