SEA SICKNESS
Seasickness is a form of motion sickness characterized by a feeling of
nausea and, in extreme cases, vertigo experienced after spending time on a
craft on water. It is typically brought on by the rocking motion of the craft.
Some people who are particularly vulnerable to the condition can feel seasick
simply by setting foot on a boat, even if the vessel is in dry dock.Others are
relatively immune, or become immune through exposure.
Seasickness can be a
debilitating condition and can be dangerous if the sufferer has an important
role to carry out, such as steering a yacht through stormy seas while avoiding
rocks and other hazards. It is also particularly hazardous for scuba divers
who, through dehydration following vomiting, are at increased risk of
decompression illness.
Cause
Seasickness is not a virus and there
for you cannot "catch it". Most people are affected by motion sickness to
varying degrees. There are certain treatments that may help to prevent the
onset or at least shield you from the very worst effects of
seasickess.
There are three seasickness triggers guaranteed to cause
suffers uncomfortable symptoms. These triggers should be avoided whenever
possible during the initial boarding and first few hours at sea:-
*
Going below deck for extended time periods. Not easy if the weather is poor
and impossible on some boats such as hovercraft. At least try to find a window
or porthole and keep your eyes gazing at but not fixed on the
horizon.
* Looking through binoculars for anything longer than a
glance
* Reading a book, looking at a compass, doing detailed work or
staring at one point. Try to keep your peripheral vision out on the horizon
and not staring at objects your brain will interpret as stable.
Human
beings instinctively seek to remain upright by keeping their centre of gravity
over their feet. The most important way this is achieved is by visual
reference to surrounding objects, such as the horizon. Seasickness often
results from the visual confusion on a moving craft, when nearby objects move
with the motion of the craft. Because the lines of the masts, windows, and
furniture on a ship are constantly shifting with respect to fixed references,
humans can suffer a number of afflictions, especially those unaccustomed to
being at sea.
Sea-sickness has such a remarkable effect because both the
sense of sight and touch are disturbed by the motion of a craft on water. The
severity of seasickness is also influenced by the irregular pressure of the
bowels against the diaphragm as they shift with the rising and falling of the
ship.
In his book The Human Body, Isaac Asimov related the anecdote about a
seasick passenger whom a steward cheerfully assured that nobody ever died from
seasickness. The passenger muttered, "Please--it's only the hope of dying
that's keeping me alive."
Prevention and remedy
Over-the-counter and
prescription medications such as dramamine and scopolamine (as transdermal
patches and tablets) are readily available. Ginger capsules are also
considered effective in preventing motion sickness. Some sufferers find that
wearing special wristbands helps stave off the condition.
Those suffering
from seasickness who are unaccustomed to the motion of a ship often find
relief by:
* keeping their eyes directed to the fixed shore or horizon,
where possible
* lying down on their backs and closing their
eyes
* drinking any substance that is likely to temporarily diminish
their senses of sight and touch
* move into a position where fresh
air is blowing on their face
* sucking on crystallised ginger,
sipping ginger tea or taking a capsule of ginger.
* moving to the
boat's center of gravity to eliminate motion due to pitch, roll and yaw (but
not translation)
* taking the helm of a yacht can reduce sickness as
the sufferer has something to concentrate on, and can also anticipate the
movement of the vessel
Unlike with a hangover, succumbing to nausea
normally does not relieve the symptoms of seasickness, and, once started, is
often difficult to stop.
