This has to be the ultimate 'must not do' list for anyone who has a spinnaker! Unless you want to trash a spinnaker (perhaps it's getting a bit past it, but you're struggling to justify the cost of a new one!), in which case go ahead!
Sailing is often portrayed as the ultimate serene activity – no engine noise, just the breeze tugging at the sails and the hull bobbing gently across the waves. But when it comes to sailing footage on Youtube, the most popular clips show nothing of the sort!
Spinnakers are the ultimate racing sail – as light as a parachute and just as effective at filling with wind. So when it comes to racing with the wind blowing from behind the boat, the one with the biggest spinnaker, usually goes fastest.
But controlling the boat downwind is a much more difficult exercise than it is when going into the wind. With the sails pulled in tight, it's simple to ease the sheet and reduce the power. But with the sheets already eased and the wind gusting from behind you... what options do you have?
In the first broach, the crew should have released the boom vang (or kicking strap) and also the halyard at the top of the spinnaker. Often this is the only way to dump the power from the huge out-of-control sail off the bow of the boat.
But as long as the rig stays upright and nobody goes overboard, these sorts of events usually sort themselves out and the crew is improved as a result.