When I got into the office this morning I did some more checking on American Oystercatcher high counts. According to Birds of New Jersey, fall high counts include 375 at Brigantine September 13 1996 and 350+ at Hereford Inlet October 25, 1994. I then checked the all time high count for NJ on E-bird - 500 on September 26, 2006 at Stone Harbor Point, reported by Willliam Keim.
Stone Harbor Point, Hereford Inlet, and Nummy Island are all more or less the same place - the complex of barrier island, salt marsh and estuary between Stone Harbor and North Wildwood, and extending inland, a marvelously rich area. Yesterday we counted our oystercatchers all from one point - well, technically two points, from each side of the base of the free bridge to Nummy Island. One wonders how many oystercatchers an aerial survey would find. Check the tide, pick low or close to it, and go, it's a wonderful spectacle!