Anybody lost about 15' of chain in Coconut Grove?

Picked this up at some point over the last few days... 15' of chain and a piece of line. I suspect it was when leaving the shallow water dock after fueling as I heard a slight knock. The suction must have pulled the line off the bottom and the chain followed No vibration at hull speed despite the unbalanced mass!

Biscayne bay is still full of floatsam, sunken or beached boats and masts ...

No but I wanted both props checked. So much trash everywhere here I ve developed a small vibration at speed. Neither have any apparent damage besides the scratches from the chain

A few years back while backing into a slip with the 70 I used to run, I picked up a chuck of concrete about a cubic foot with wires, rebar and conduits sticking out. Big Bang, locked the shaft but no damage. Funny thing is that I had been backing into that same slip for a couple of years