a) Early form of motive power, less than 1hp, for inland waterborn transport
b) http://www.wcbs.org.uk/
c) It's about 4 meters (12') long - i.e. "I would not touch xxx even If I were able to remain at a considerable distance and thus leave my person unsullied"
;-)
I think I have one. It is a ten foot boathook with a steel spike on one end, useless for picking up moorings, never to be used near other boats, but invaluable in locks or near steel commercial craft....