It was a tight squeeze, with large yellow signs on both lock gates saying to keep back from them. It was all going fairly smoothly until I suddenly felt the tiller push firmly to one side. I initially worried we might be snagged on something, but it turned out to be a strong current. One of the top paddles must have been slightly open, so there was a strong jet of water which the rudder had just descended in to. I asked Clare to try to lower that paddle, which fixed the problem - and probably made opening the gate easier too.