Fish n chips, and Bill Cody. I'll give the cinder blocks a try on the uphill side.
I have to admit, I wasn't sure where to place them, but Bill's details helped.
Thanks

9 yr old pond, 1 ac, 15' deep.
RES, YP, GS, FHM (no longer), HBG (going away), SMB, and HSB (only one seen in 5 yrs) Restocked HSB (2020) Have seen one of these.
I think that's about all I should put in my little pond.
Otter attack in 2023