The Austrian's City of Wiener Neustadt was five miles offshore going through the Straits of Dover when the mast crumpled at the first spreaders. "We were very lucky no-one was injured," he said.
The mast is being repaired in Southampton and Hanakamp hopes to start on Tuesday. The other nine yachts leave today.
In Rio de Janeiro, Mike Golding was held up for nearly 14 hours by light winds before taking Group 4 across the line first at the end of the first leg of the BT Challenge. His time of 26 days, three hours was three days shorter than the best time in the 1992 inaugural circumnavigation for fare-paying amateurs.
Less than three hours behind was Simon Walker in Toshiba while 500 miles back and last was James Hatfield's Time & Tide.