The plovers near the water were accompanied by hundreds of Dunlin and Sanderlings, but the plovers tended to keep their distance from the two sandpiper species and not mix with them in any significant way.
I checked each of the plovers as carefully as possible for any sign of bands or color markers on their legs, but I did not see any. Some Piping Plovers that winter in the Bahamas have been marked with colored plastic bands; if you happen to see one, report it following the directions at the link. One that was sighted by Andrew on Long Island last year and then re-sighted in the Bahamas; at least one Bahamas plover has already been reported this spring in Connecticut.
As a bonus, here are a couple of American Oystercatchers that were in the same area.