Marie Higgs - How Deep is the Ocean?

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The primative man discovered he could fish in deeper water when he placed himselfon a tree trunk and ventured out into the deep water. Needing some place to put his catch he hollowed out his log then added a paddle to guide his craft where he wanted to go. Later when boats and canoes travelled even further afield they needed to know how deep the waters were in places they had not been before.

At first they used a Sounding Pole marked in sections, but they could only carry one the length of their vessel.

About 3,000 years BC Egypt was bulding large ships capable of going to sea for long periods of time, and like people today wanted to go even further to discover what lay beyond the horizon. Using Sounding Poles along the coat lines was alright close to shore but theyneeded something less cumbersome for longer journeys to strange lands.

Obviously they needed something more portable s a rope to which they tied a large rock was used; so much easier to store on board.. When the stone hit the bottom of the ocean or reached its full length, they hauled it up and measured the length of the rope. This wasn;t done with a ruler, but rather the same motion a draper did when sizing cloth. The span of a man's arms would be roughly  six feet.

Much later in the time of the Norsemen who watching this motion likened it to the embracing of a girl, called the measurement a FADOM- meaning embrace- and passed this word onto our language as FATHOM, and this in turn has come to mean a six foot interval of depth.

Of course science has advanced in the interim and  now we have depth finders/computers which measure the ocean floor as the ship travels over it, but the measuring rope is still used in smaller craft in other countries.

So the next time you hear a call like - 'mark 6' you will know that they mean there is six fathoms of water below the hull.

M. Higgs

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