You recovered my board twice after I lost it on the far side of the channel, cheers. I owe you a beer, or several.
No worries mate... no beers needed. When I was a beginner I had my board recovered a couple of times... just paying it forward.
There's a pretty strong outgoing current in certain parts of the river mouth and you happened to be right where it was running. Get some hardcore body dragging down and you'll be good :)