Interesting reading on Morts blog Bones regarding magnets, brings to mind our use of the sea searcher magnet on the Rochdale Canal recently.
We had moored for the night at Irk Aqueduct as suggested by BW ready for our shadowed passage down the Rochdale 19 locks the following morning. There were three boats moored including ourselves with Nb Epiphany and a Sowerby Cruisers hire boat. Hearing a noise at around 8pm and a slight movement of the boat, Derek and I were out in time to disturb some youths letting off two of our three ropes. The hire boat (which was empty at the time) was adrift on the other side of the canal.
How to retrieve it and secure it again? Derek threw our sea searcher magnet attached to a long rope onto the cruiser deck of the other boat. It made contact and slowly we managed to pull it back to the towpath and resecure the ropes. How about that? What weight is a narrowboat and the magnet held tight.