In the third movie (“At World's End”) in the Pirates of the Caribbean series, Jack Sparrow and his crew need to roll their ship (the Black Pearl) over in order to bring it back to the living world during a green flash at sunset. They do so by running back and forth from one side railing to the other on the top deck. In addition, Captain Barbossa orders that 18 cannons and a pile of barrels on the lower deck be cut loose to add mass to the running crew. In the movie they overturned the ship, but would they succeed under the same circumstances on a real galleon? In this paper, a numerical analysis using simple approximations is developed that suggests that what occurs in the movie is in fact realistic. Analyzing a popular film clip in this manner is a good way to arouse student interest, to teach about physics and numerical methods, and to model scientific reasoning when a situation is not as neatly defined as in a typical textbook problem.

1.
en.wikipedia.org/wiki/Black_Pearl.
2.
en.wikipedia.org/wiki/Japanese_warship_San_Juan_Bautista.
3.
www.hms-victory.com/index.php?Itemid=105&id=72&option=com_content&task=view.
4.
blindkat.hegewisch.net/pirates/pirateships.html.
5.
A. Biran, Ship Hydrostatics and Stability (Butterworth-Heinemann Elsevier, Burlington, MA, 2003).
6.
J.
Mégel
and
J.
Kliava
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Metacenter and ship stability
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738
747
(July
2010
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A.
Cromer
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Stable solutions using the Euler approximation
,”
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459
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1981
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Also see
T.
Timberlake
and
J. E.
Hasbun
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334
339
(April/May
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8.
S. F. Hoerner, Fluid-Dynamic Drag, 2nd ed. (Hoerner Fluid Dynamics, Midland Park, NJ, 1965). Also see W. F. Hughes and J. A. Brighton, Schaum's Outline of Fluid Dynamics, 3rd ed. (McGraw-Hill, New York, 1999).
9.
J. W. Brasher, W. L. Christensen, and V. W. Rinehart, 1986 Annual Report of the National Shipbuilding Research Program, online at www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA454077.
10.
Use the formula in Eq. (11) for air resistance with ρ= 1.2kg/m3 (for moist air at sea level) and C = 1.2 for a square plate at high Reynolds number. Many of the sails are oriented perpendicular to the length of the ship and thus do not contribute to the rolling drag. From the movie we estimate a net lateral area for contributing surfaces of about A = 200 m2 at a mean height above the water of about d = 15 m so that β = 5×105 N⋅m⋅s2, comparable to what we calculated for the keel.
11.
M. Denny, Float Your Boat! (Johns Hopkins University Press, Baltimore, 2009).
12.
The Vasa Museum, online at www.pkvirtual.com/virtual/prace/vasa1.pdf.
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