500 ATLANTIC COAST TIDES 



respectively. The continental shelf in this bay is widest off 

 Sandy Hook, where it is channeled across by the submerged 

 valley of the Hudson. Tidal ranges increase from about 2 feet 

 at Nantucket and Hatteras to more than 4 feet at points on the 

 Jersey shore and at Sandy Hook. 



The extreme difference of times throughout the bay is about 

 an hour, the distribution being somewhat irregular. There are 

 three points of early, almost simultaneous, high water — 



No Mans Land, near Marthas Vineyard ; 



Fire Island inlet, on the south coast of Long island ; 



Cape Hatteras. 

 At four other points high water arrives almost simultaneously 

 an hour later : 



Nantucket, south shore ; 



Montauk point, entrance to Long Island sound ; 



Delaware Bay entrance ; 



Chesapeake Bay entrance. 

 Between these points there is a good progression of times from 

 early to late. It will be noticed that the entrance to New York 

 bay is not a late point, like the Delaware and Chesapeake en- 

 trances, yet there is some delay from Fire island to Sandy Hook. 

 In general, the time differences are of a magnitude perfectly ex- 

 plicable by variations of depth and shore configuration. The 

 expectation that weak tides should early reach the headlands, 

 Nantucket and Hatteras, and progress thence toward the bay 

 head is not realized, save for amplitudes. The times are as early 

 within as at the bay headlands. The amplitudes do increase up 

 the bay. 



This portion of the American shore is nearest to the swaying 

 ocean, with its ebb and flood currents alternating along the shore- 

 The characteristic of the coast-line is longshore transportation, 

 cut headlands, and long beaches and bars, to which the soft ma- 

 terial of the coast readily lends itself. The only considerable 

 interruptions in the continuous beaches from Montauk point to 

 Hatteras are at the remoter portions. These openings are aided 

 at New York and New Jersey by the stronger tides, and at the 

 Chesapeake by the outflowing waters of the northern half of the 

 Appalachians. 



SOUTHERN BAY TIDES 



The shores here have three types — the cuspated capes in Caro- 

 lina, the Georgia entrances, and the Florida sand bars. The tide- 



