The 1998 Sydney to Hobart race was decimated by large seas and strong winds, killing 6 competitors and leaving many injured and / or drifting at sea inside and outside of life rafts. 55 people rescued from sailboats, 5 boats sank and 66 boats retired out of the 115 starters when multiple storms merged and hurricane force wind and waves descended on the fleet. Conditions reported by the sailors and rescue crews during the hight of the storm were 90 knot winds and 30 meter (100 foot) waves.

These conditions are not uncommon in Bass Strait.

Below is a great link to stories and pics of monster waves.
http://dode777.jeeran.com/announcement_page1.html