Good Day Bryon: On observing the tracking charts for the Vendée Globe yachts, you will see a limiting line, encircling the Antarctic, basically known as the Ice Limit.  Yachts racing in the Vendée Globe risk a penalty for entering this zone.

Reason is because of ice.  In the Southern summer months ice bergs break away, known as calving, from the Antarctic ice shelf and tend to drift North and East with the various Southern Ocean currents.  For a large container ship with sophisticated radars, sighting of these bergs is not a problem.  However with the Vendée Globe yachts, they do not keep a full 24 hour lookout.  To further the problem, these bergs disintegrate so that small chunks of ice float well away, these chunks being known as ‘growlers’ or ‘bergy bits’.  While not overly large, any yacht striking one of these chunks of ice while at racing speed, would almost certainly sustain dreadful damage and probably sink very quickly.  It must also be remembered that about 9/10 of any ice is submerged and thus with height of eye on a yacht being very low, small pieces of ice would be so hard to sight.

Note how close the racing yachts limiting line is near Cape Horn, bottom of South America.  I understand that if ice was sighted North of the aforementioned limiting line, the Vendée Globe race officials can move the ‘limit’ further North.

– Question submitted by Byron, Hancock, United States