Standing on the ocean beach in Montauk with East Hampton Town Supervisor Larry Cantwell on Tuesday, the question was why the downtown waterfront strip is the way it is. High waves from Hermine, a post-tropical cyclone by the time it passed Long Island last week, had eaten away almost all the fill that a United States Army Corps of Engineers contractor had placed there in the spring. As we looked over the damage, Larry pointed out that the sand level was more or less back where it had been when the corps project began.