IMO I see a home made anchor. Right at 40 yrs ago I started using a Danforth Boat Anchor rated for a 15,000 lb boat. 18" wide, 24" long, 5" high, weighs 20lbs, stores flat at 5" high. It has served me well over the years, use the truck to pull it into/out of the ground. Buying new will give a heart attck $$$, used if your patient get a good deal.