I have always suspected the so called
Caribbean Rapiers were actually not caribbean made swords but Spanish navy trooper swords.
Some underwater footage from the wreck of the galleon San Jose, sunk in 1708, backs this idea. The site is 600 meters deep underwater, so you get less oxygen for oxidation and less fauna for crusts.
See at 39 seconds:
https://www.youtube.com/watch?v=bTcKZgn7Whk
At the same wreck there are also examples of the officer version, the two shell rapiers.
See at 59 seconds:
https://www.youtube.com/watch?v=LW9TzSVvBUM
Identified naval wrecks are helpful for an
ante diem datation of weaponry.
For example, in the war of the Spanish sucession (1700-1714) French supplied the weaponry of many Spanish regiments with French models from St Etienne and Charleville manufactures. However there are no survivors of these weapons and Spanish authors ignore the subject alltogether. But there are exceptions... underwater relics.
The picture show French naval sabres hilts found at the Nuestra seņora de Guadalupe galleon, sunk in 1724.
This is the subject of a book I ordered recently.