From: Dave Lawrence
Subject: Islands
To: (a mailing list of riding buddies)
Date: Thu, 15 Nov 2007 12:11:37 -0500

On a recent trip to Bar Harbor, a whale-watching guide made the claim
that Mt Desert Island is the third largest island on the eastern
seaboard.  This same claim can be found frequently on the web.

It naturally caused the following questions to spring to mind:

* Did they mean the eastern seaboard of just the USA?  Apparently yes,
  because otherwise the claim would quickly be disproven by several
  Canadian islands.

* What were the first two in the USA?  Long Island seemed obvious, but
  the other?  Maybe something at the Outer Banks?  Something off of
  Florida?  Martha's Vineyard?

After the trip I promptly forgot the question, til recently when I
started pondering whether Cape Cod is an island.  My gut says yes, but
I am completely prepared that there is some semantic reason why it is
not.  Reasons I could think of that could possibly disqualify it from
island status include:

* Not surrounded on all sides by water.   This one is clearly false,
  as the completion of the Cape Cod Canal not only surrounded the land
  area on all sides by water, but also by water fully navigable by
  large ships.

* Too large an area.  Also clearly false, as there are many islands
  much larger than Cape Cod (about 413 square miles).  No one seems to
  dispute that masses like Madagascar or Sumatra are islands.

* Man made water courses don't count.  If so, Zug Island in Detroit
  and many, many other similar features shouldn't be called islands.

* Water depth matters.  Maybe it does, but it doesn't seem to
  disqualify many other islands (though I have no specific cites for
  this, here I am just going on my own experience).

* Ratio of width of body of water to separated land mass matters.
  This seems plausible, because it does affect perception of
  "islandness" strongly.  Yet it might seem to disqualify many
  accepted islands, including Long Island because of its comparatively
  very narrow separation by the East River.

The more I thought about it, the less I could disqualify Cape Cod as
an island.

So while trying to figure this out, I came across:

http://en.wikipedia.org/wiki/List_of_islands_of_the_United_States_by_area

Looking down the list, there are no candidate islands ahead of Mount
Desert Island other than Long Island, unless you count Puerto Rico
which seems a real stretch for "eastern seaboard".  And Canada clearly
wasn't meant to be part of the "third largest" claim as noted above.
Martha's Vineyard was close, but 17 square miles smaller (though some
sources claim 100 square miles, perhaps including 5 square miles of
Chappaquiddick and some additional tidal area, making it only 8 square
miles smaller).

About the only way the Mount Desert Island claim can stand is if Cape
Cod is really an island, jumping it to position 22 on the list at the
wikipedia page.  I'm sort of surprised the guide didn't point out this
remarkable fact; maybe he just figured it was common knowledge.

But since it doesn't appear to be, I hearby declare Cape Cod to be an
island.  It is _clearly_ the only way to resolve all of this
satisfactorily, with no alternatives being remotely possible.  I'd
appreciate your cooperation in calling it by this new moniker.  I'll
be updating the wikipedia page.  "Island Cod" sounds stupid though and
there are already a couple of Cod Islands, so I will take some
inspiration from our Quebecois friends and dub it Ile d'Cod.

Argue.

(Real conclusion: the term "island" is poor specified and probably
doesn't have a real scientific definition, just one of perception.
And if I *really* need to more distinctly label the "_clearly_" bit as
tongue-in-cheek, then I weep.  But I still want to see you fight over
whether Cape Cod really is an island or not.)