GIANT WAVE - The Lighthouse - page 87

One possibility put forward is that a rogue wave phenomenon known as the 'Three
Sisters' occurred in the area at the time the ship sank. The 'Three Sisters' phenomenon
is three rogue waves close together and on average one third higher than all the waves
surrounding them. It is surmised that these hit the ship one after another. The first one
probably hit the ship and swamped it and before the water had time to drain away, she
was hit in rapid succession by two more of these huge waves which caused her to sink
immediately. The deck would have become overloaded with literally many tons of wa-
ter, which the ship could not sustain.
To give some credence to the 'Three Sisters' wave possibility, the Captain of the Ar-
thur M. Anderson had reported that his ship had been hit by two 30-35ft (10m) waves
which had buried the aft cabins and damaged a lifeboat. The second of the waves had
gone over the bridge deck and the captain stated that these waves were possibly fol-
lowed by a third large wave, had continued in the direction of the Edmund Fitzgerald.
Inthefewhoursbeforeshesank,CaptainMcSorleyofthe Edmund Fitzgerald hadbeen
in radio communication with the US Coast Guard and the Arthur M. Anderson. He had
reported at 3.30 p.m. that day that his ship was taking on water and that she was listing
as well as having lost two vent covers and a fence railing. More seriously the ship had
lost the use of both radars. Very early that same morning, the weather service had up-
graded the weather status from gales to a storm warning.
That afternoon, the weather worsened and the waves increased in height. It was in
this considerably weakened state, with a severe list, that the ship was hit by the 'Three
Sisters'. The last communication with Captain McSorley was at 7.10 p.m. when the
captain of the Arthur M. Anderson contacted him to ask how he was doing. McSorley's
response was 'We are holding our own'. The ship sank almost immediately after this
exchange. Ten minutes later the captain of the Arthur M. Anderson could not raise her
on the radio or see her on the radar.
The loss of the Edmund Fitzgerald was highly significant for a number of reasons,
notleast beingthesuddenness ofherloss,andthushasattracted agreat deal ofinterest.
She was the largest vessel to have sunk in the Great Lakes and the findings from her
loss led to a number of changes in shipping regulations on the lakes, including more
frequent inspections of vessels, depth finders, increased freeboard, positioning systems
and mandatory survival suits. 20
It may come as a surprise, considering how long man has encountered giant waves,
but the causes of rogue waves are still the subject of active research. It is important to
separate giant or rogue waves from tidal waves, which are a completely different phe-
nomenon. It is still too early to say that there are any firm conclusions as to what the
common causes of these rogue waves are or whether the waves vary from one place to
another. Rogue waves appear in bad weather conditions when the average wave height