Pulled out this gnarly looking anchor from right in the middle of the canal junction before the CRT bridge operator came out and told me I wasn't allowed to magnet fish in the canal. After that I walked 100m down the towpath and pulled out all of this stuff:
First trip out with the massive Barbarian magnet and it's definitely better at sinking down into the mud, although I don't think I'll be doing full 20m casts with it without a lot more practice.
Magnet fishing is pretty cool! I was out (regular) fishing one day and there were some kids magnet fishing off the side of the dock. The dock was this giant metal structure with metal fencing around it. On one of their tosses, they pulled up an entire length of that same metal fence from the bottom of the creek. My guess is someone knocked it over or dropped it into the creek when the dock was being built. Then a little while later I saw them pull out a fishing rod I'd watched someone lose in the creek the week before. I felt pretty lame trying to catch a stupid fish with these guys pulling up all this buried treasure
Steel fencing is common to use for bank soil retention.