Chapter I]—GEOGRAPHICAL AND PHYSICAL CONDITIONS. 
1. GEOGRAPHY. 
The general geographical features of the region may be seen at a glance by reference 
to charts 223, 224, and 225%. Vineyard Sound has a length of from 15 to 17 nautical 
miles, depending upon the limits arbitrarily chosen,’ and a width of from 3 to 6 nautical 
miles. Its main axis bears from northeast to southwest. The southeastern boundary is 
constituted by the island of Marthas Vineyard, the northwestern by the Elizabeth Islands 
and for a short space by the mainland of Cape Cod. At its eastern end Vineyard Sound 
passes imperceptibly into the far wider Nantucket Sound, while to the westward it 
opens freely to the Atlantic Ocean. It is connected with Buzzards Bay by a series 
of narrow straits, of which Woods Hole isatype. Through them the tidal currents are 
very swift. These straits separate the Elizabeth Islands from the mainland and from 
one another. There are no streams of any consequence emptying into either Vineyard 
Sound or Nantucket Sound. 
Leaving out of consideration certain shoals and the zone immediately adjacent to 
the shore line, the depth throughout Vinevard Sound ranges between 6 and 18 fathoms, 
most soundings lying between 10 and 15 fathoms. There is in no sense a progressive 
deepening of the water as we pass toward the western end of the Sound, although some 
of the greatest depths (18 fathoms °) occur in the vicinity of Gay Head and Cuttyhunk. 
At least one sounding as great as this has, however, been made back of Middle Ground 
Shoal, and depths as great as 17 fathoms occur at more than one point in the eastern 
half of the Sound. Asa rule, the 10o-fathom line runs within a half mile from shore, 
though mention must be made of an elongated shoal reaching well toward the middle 
of the Sound and extending throughout about half its length. This is known at its 
eastern end as the Middle Ground, the opposite end being called Lucas Shoal. In the 
former portion the water may be no deeper than 4 feet or less in depth at mean low tide. 
Buzzards Bay has a length of about 25 nautical miles, as measured from the railway 
station known as Buzzards Bay to the Hen and Chickens Shoal. Its main axis is nearly 
parallel to that of Vineyard Sound, from which it is separated throughout the lower 
half of its length by the Elizabeth Islands. Elsewhere it is bounded by the mainland of 
Massachusetts. At its northern end and along its entire western side the shore line of 
Buzzards Bay is very irregular, being indented by a considerable number of estuaries, 
a’These and other geographic and hydrographic charts used in the present report are the work of Mr. W. F. Hill, formerly 
draftsman in the Bureau of Fisheries. 
b The region explored during our dredgings extends a short distance into what would probably be commonly regarded as 
belonging to Nantucket Sound, though there is, of course, no definite line of division between the two. 
¢ Our own soundings give 19} fathoms at one point (Fish Hawk station 7683), while the greatest depth indicated on the Coast 
Survey chart for Vineyard Sound is 18 fathoms at mean low tide. Perhaps the phase of the tide is partly accountable for this 
difference; perhaps it rests upon an error of observation. The depth recorded by us for station 7682 (19 fathoms) is quite likely 
due to an error. Otherwise no serious discrepancies have been detected between the Fish Hawk soundings and those of the 
Coast Survey. In general our soundings (Fish Hawk and Phalarope), while not always taken with great care, are believed to 
be close enough approximations, especially when the variability in depth throughout the extent of the Bay and the Sound are 
considered. 
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