Went to Coastal a couple of times over winter and got told about the proposed extension over the ditch. Haven't yet seen it in person, but it could make a good track into a great track!!
It is a voltage protector, same as the one at the bottom of the link
http://www.spektrumrc.com/DSM/SurfaceProducts.aspx
Got mine from Kellers in Norwich, but any decent model shop could get you one.