Vintage 1980's NOS Stainless steel? Boat Flagpole socket Holder

From a Pet/smoke free home. Please examine the photos and video closely prior to bidding.  Found this item in a plastic bag of old boat parts I had. Appears to be NOS. I believe it's stainless steel and that it may be a boat flagpole socket/holder. Any help in identifying it's functionality would be appreciated. Measures Approx  2 1/2'" in Length. The base is 1 1/2" x 1 1/4" The hole is approx 7/8" in diameter


This item is sold as is. Free shipping to the US.