How to get out of that
To get out of a broach you need to regain steerage by getting the water to flow over the rudder again. Many helmsmen will hold the tiller to windward hoping that it will eventually bite but it is actually better to make large aggressive movements of the rudder to the centre and then to windward. This will work best in the early stages of the broach as long as all the sails are free to flap, thereby reducing the pressure holding the boat over.
Once pinned over, the only solution is to release the pressure from the spinnaker or to take the spinnaker down completely. It is essential not to release the guy because once released, it gives the spinnaker more leverage to hold the boat over.
Dropping the spinnaker requires good communication between the crew and a good understanding of who does what and when.
The bow team and pit need to work together to make it happen as smoothly as possible.
The first option is to trip the kite. Try just releasing the halyard a bit – sometimes this is enough to pop the boat back up and permit the helmsman to bear off. If that doesn’t work you need to continue to get the kite down.
Before the kite drop/retrieval manoeuvre begins, and to ensure the spinnaker doesn’t end up in the water miles from the boat, it is important everyone on board is aware of