I have a 24' Mac and am new to all this, I have a spinaker but never attempted to try it yet, I hear of people being afraid to fly them, why? What can happen? I've seen a few videos of boats doing nose dives but they were ocean racing with big waves, I'm in small inland lakes and rivers with a blue moon trip to Erie.
My suggestion to all those new to spinnakers ( and especially when I am training new crew) is to practise with a piece of rope first, so that everyone gets the picture of how the boom works in conjunction with the forestay especially when gibing or taking it down. I get a piece of rope (usually twice as the length of the mast or forestay) then double the rope so that you have a loop in the middle and then tie a knot about 1 foot down from the loop so that you have the head and then tie a knot in the two trailing ends about 10 to 20 feet from the end (depending on the size of your boat) and then tie a loop in the end of each tail to make the clews and this is then your practise spinnaker. Show everyone how it is attached to the halyard, the sheet, and then through the end of the pole to become the guy. When ready haul the halyard to the mast head and then manually stretch the pole away from the sheet which gives everyone and understanding of the scope of the sail and how it will handle when hoist.
There is then an opportunity to work through the actions to be taken to gybe - where you stand to start, when you move, how does the sheet become the guy and alternatively the guy become the sheet, and do you remove the pole in the process or just "dip" it. It can be all done at your leisure and whilst on the mooring, so that everyone gets comfortable with the mechanics before you ever try it in "anger". For reference when dropping, it is always easier to get a hand ready to take the sheet and then release the guy from the pole and the spinnaker will fly off and give the person on the sheet the opportunity to tell the person on the halyard to lower slowly so that they can gather in the spinnaker. I have some pictures if you wish to contact me.
Malcolm@mavbrock.com