Seamanship_Secrets_185_Tips_-_Techniques_for_Better_Navigation-_Cruise_Planning-_and_Boat_Handling_Under_Power_or_Sail_(Re)_e..

286 seamanship secrets

temperatures along the central and southern Atlantic coasts. In the British Isles,
water temperatures in early fall range from 14°C (57°F) to 18°C (64°F). Winter water
temperatures can plunge below 10°C (50°F). Mariners in wintertime must wear
anti-exposure clothing and have survival equipment ready to use in an instant.

How Heat Loss Accelerates in Cold Water
Three things happen within seconds of falling into water with temperatures
of 77°F (25°C) or less:

1. Th e body sends huge quantities of blood from the core to the shell area in
   an attempt to warm up the skin layer.


2. Th e shell area shrinks to shorten the distance the blood has to travel to get
   to the skin. It tries to help—but the end result is just the opposite! Th e core
   becomes more exposed because of less shell insulation.


3. Th e warm blood near the skin transfers heat to the surrounding water. Th e
   blood cools near the skin and fl ows back to the core, cooling it in turn. Th is
   cycle continues back and forth between core and shell. Th e longer you stay
   immersed, the cooler your core becomes.

Cold-Water Shock and Loss of Motor Skills
At 2:20 am, Monday, April 15th, 1912, the Titanic slid beneath the waves of the
Atlantic, leaving her passengers and crew fi ghting for their lives in 31°F (–1°C)

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Montauk, NYAtlantic City, NJLewes, DECape Charles, VABaltimore, MDAnnapolis, MDCape Hatteras, NCCharleston, SCSavannah Beach, GADaytona, FLMiami Beach, FLKey West, FL

Seawater Temp.

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16

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4

–1

–7

–12

–18

21

°F °C

Winter seawater temperatures on the central and southern Atlantic coasts.