We reached the Seine River today, Wednesday. Things had gone well, but when we used the bow thruster, it failed. The bow thruster is used to move the bow from side to side. It is mainly used to maneuver in difficult situations.It sounded as if the propeller had fallen off, but we were able to check that was not the case. This was a little hard to do without swimming (the water is WAY too cold for that.We moved to a pontoon in the town of Montereau. I then spent 6 hours crammed into a tiny space in the bow, removing the motor from the thruster. The motor is huge, hard to reach and weighs 60kg. I had to bolt some garden stakes together and make a block and tackle from the rigging on the boom. Once the motor was off, the problem was found to be in the gearbox which is underwater. So, the boat has to be lifted out.We have decided to do without the bow thruster and see how we manage. It would have been tough today in sloping sided locks with a very strong cross wind. We found that we are just not strong enough to push 36 tonnes of boat with poles, against the wind.The other challenge will be getting into the packed arsenal Marina in Paris, particularly if there is a strong wind. We go up the Petite Seine tomorrow. This is the head water of the Seine.More later. Regards,Dave (and Penny)