Ah, are you a boater too. Terribly exciting lifestyle.
TBH most cyclists are considerate - I rarely use the canal, but when I do I pass other users slowly, with an 'excuse me' and a 'thank you', only takes the 'odd idiot' to tarnish everyone. Talks of throwing cyclists in to the canal aren't funny as a user on here got exactly that.
If some one did that to me, I'd either jump out and welcome the attacker to the tepid waters, or the buggers would be pinned down until I got hold of a copper, then charged with assault, and a big repair bill.
No-one seems to like anyone who uses different forms of transport from themselves, so many selfish buggers about, including boaters would you believe.