I put down a mooring 3 years ago that is still holding, although it's now another boat. When I switched to a 45lb manson supreme I surplused a 45lb cqr
and a 66lb bruce. This is in a tidal river on the icw
with the current
alternating north and south. I connected the two with 100 ft of chain and connected a vertical chain at the midpoint for the mooring ball. Then I sunk it north and south on the river so that each anchor
is taking the strain depending on the tidal flow.
Others in the anchorage use brake drums from large trucks. They are fairly common in junk yards in florida
because, or so I've been told, they cannot be reground, they must be discarded. They are pretty heavy and are easily linked together with chains. They bury well in the deep mud we have. They're also cheap
. I know of one that has been in continuos use here for at least 6 or 7 years.