Hello! My first post as I've just discovered this forum. In October I had the great pleasure of narrowboating for the first time when we hired a 50ft narrowboat for a long weekend.
On our first passing through Braunston Tunnel, I just chugged along a discrete distance behind a boat in front. On the way back, I had a clear view all the way through. I set the throttle reasonably low for a quiet life and found I was making reasonable, if not amazing progress. However, there was a boat coming up from behind at quite a pace and it had caught me by the middle of the tunnel, in spite of my moving the revs up a notch. If anything, I seemed to lose boat speed relative to the tunnel, especially when the following boat came within a few metres of my stern. I'm not sure what was happening to my speed through the water though. I then heard a somewhat impatient shout telling me to "get a move on!", to which I replied that this was my maximum speed. I pushed the throttle forward more, but just got a louder noise. A couple of questions:
1) As a matter of etiquette, should I have tried to let him past? I would not have been confident in steering the boat tight alongside the wall for the amount of time it would have taken, accounting for his wash etc. I pulled over as soon as we were out of the tunnel.
2) Is there something hydrodynamic going on, which means I lose boat speed when another boat is close behind. Something like generating a local counter-current so the boat squats down in the water more and has to climb a steeper bow wave? Or could it be that the prop was not suitable for the higher revs and was just churning the water or cavitating?