Reminds me of a holiday job I had when about 18 or 19 as a boat driver at Chester Zoo..
Folks would be charged about 30p each to be driven around the canal in the zoo on an old lifeboat so they could get a different view of the animals.
However, there were a number of bridges en route where occasionally little scrotes would wait and drop things or spit on the passengers. A couple of us, being young and fit, discovered we could put the boat into reverse just before the bridge. Then we'd leap up and over the fence, little scrotes would scatter and then we'd jump back on the boat as it emerged on the other side to (hopefully!) cheers and tips from un-spat-on punters.