Weird anchor

I picked up a Mirror Dinghy today for free. The owner included a weird anchor that he didn’t know anything about.

It looks like a basic mushroom anchor, but is made of plastic. It weighs nothing. The shank is hollow and unscrews from the base. It is 10” high and about 9.5” across at the base. The only name on the anchor is “MOD. DEP.” I can’t imagine this weighing much even if the shank was filled with lead shot. Any ideas how this was used? Thanks.

Looks like it would be popular with the drug runners.

My guess would be that it is a prototype,possibly.

That,I think,is a two piece mold for sand casting anchors.If you use it as an anchor it will break if it catches anything solid,that is if it will sink at all.