If you know it's the pole causing the damage for sure, I'd be going round giving the guy a bill for the repairs... There's too much of this around today on the canal, where I am there is boats moored on a bend. It has happened a lot recently where a boat travelling doesn't make the bend and collides with the moored narrowboats, which should not happen as there is plenty of room... These people that have just struck another boat then just continue on their way coming out with some excuse like 'oh the wind caught me, there was nothing I could do? ¿?'. If they had done that in a car they would be swapping insurance details, I don't see why it should be any different on the canal, damage is damage and it needs paying for...