>>120036240Survival manuals consistently advise against drinking seawater.[7] A summary of 163 life raft voyages estimated the risk of death at 39% for those who drank seawater, compared to 3% for those who did not. The effect of seawater intake on rats confirmed the negative effects of drinking seawater when dehydrated.[8] (In contrast to humans, pelagic birds and other sea animals can (and must) drink sea water without ill effects.)
Some historians have suggested that the mysterious sicknesses afflicting the early English colonists at Jamestown, Virginia (1607–1610)—which nearly extinguished the settlement—reflect sea water poisoning. The settlers arrived in the spring, when the James River water was relatively fresh, but by summer a drought of historical magnitude had rendered it much more brackish. The historical geographer Carville Earle, among others, holds to this view.[9]
The temptation to drink seawater was greatest for sailors who had expended their supply of fresh water, and were unable to capture enough rainwater for drinking. This frustration was described famously by a line from Samuel Taylor Coleridge's epic poem The Rime of the Ancient Mariner (1798):
"Water, water, everywhere,
And all the boards did shrink;
Water, water, everywhere,
Nor any drop to drink."
Although humans cannot survive on seawater alone—and, indeed, will sicken quickly if they try—some people have claimed that up to two cups a day, mixed with fresh water in a 2:3 ratio, produces no ill effect. During the 18th century, British physician Richard Russell (1687–1759) advocated the practice as part of medical therapy in his country. In the 20th century, René Quinton (1866–1925), in France, would also endorse the practice.
