unprepared
As a grad student, I was regular crew on a 44' masthead rigged Bruce Farr boat in New Zealand. It was originally built ('extra-sturdy') for off-shore racing (Sydney-Hobart), but the second owner (our skipper) was tired of being underpowered in lighter air harbor racing (Auckland harbor) so he got a new taller mast (mains'l area increased by 15%) and sails.About the 4th or 5th time out under the new rig, the breeze was around 20 kt with gusts to about 25 kt. Under the 'old' rig we would have been in our element, eating the lunches of all the flash new light displacement boats, and we treated the day accordingly - put it all up and sit on the 'high side'. On a beam reach, with our full-size spinnaker up, an extra-strong gust hit us and knocked us down (the top 1/3 of mast was submerged). We were surprised, to say tyhe least (I wish I had a photo of the skipper/owner's face as he stood up to his knees in water, still holding the wheel. Well, we reacted too slowly, and the mast broke at the bottom spreader before the boat righted itself.Sitting around that night (after a few rounds of stress-relieving rum), we all discussed how we could recover more quickly in a future knockdown under spinnaker (assuming we couldn't prevent it by making better sail selections, etc). Our conclusion was that we should release the spinaker halyard asap.The mast was slieved and rerigged two weeks later. On the very first outing after that, we had similar conditions (a bit heavier air), and ... you guessed it ... we broached and were knocked down again. However, this time the mastman immediately released the spinaker halyard and she came up immediately, with no damage - except to our pride.After that race, we decided we had gathered enough data to conclude that the boat we'd known for several years as a heavy air boat had been converted to a light air boat, and we'd better treat it as such!