Many boats already have all the deck gear necessary to fly an asymetrical spinnaker, others may need one piece of missing gear. Either way, setting up your boat to fly these colorful sails is usually a fairly simple project.
Here's what you need:
While you can raise a spinnaker with a genoa/jib halyard, many boats have furling headsails, which requires that you use a spinnaker halyard. A true spinnaker halyard is your best choice, regardless, as the block will be positioned above the headstay attachment. This minimizes chafe no matter which direction the sail is pulling from.
If you don't already have one, we highly recommend the addition of a dedicated spinnaker halyard with a free-swiveling block.
TACK / DOWNHAUL
The tack (forward bottom corner) of your spinnaker must attach to the bow of the boat. This can be accomplished in either of two ways:
- Sturdy fitting at the bow. ANY fitting you use should be secured by a hefty backing plate! Many sailors use hardware that's part of the anchor roller. If you have a heavy bar, welded to the frame, that holds your anchor stem in the roller, this can be ideal. If not, you may have to add a heavy pad eye to the bow. Be sure it doesn't conflict with your anchor, head stay, pulpit, or other hardware! Attach the tack of the sail to the pad eye or other deck fitting with a length of sheet-weight line, or wire, approximately 5' in length. You can attach line to sail and hardware with bowline knots, shackles, or a combination of both. We once flew a spinnaker on 45' boat using a dock line to secure the tack.
- Downhaul. A downhaul bypasses the problem and gives you additional control over your sail. It's a great option for bows crowded with hardware, or sailors who want to squeeze out every ounce of performance. Tie the downhaul line to the tack ring of the spinnaker, then run the tack downhaul line through a turning block on the deck near the bow. Lead it aft to the cockpit, running it through a fairlead every 5' or where needed. Secure to a cleat. Set the downhaul line so the tack will be about 5 feet above the deck the sail is hoisted. This gives you added control to lift or lower sail off the deck.
You'll need two lightweight sheets approximately 2x the length of your boat.
The sheets are led outside the lifelines (the lazy sheet, the one that will be slack, must run in front of your head stay). Both sheets should be led aft to a turning block located near the stern of your boat. From there, each sheet is led forward to a winch. Spinnaker winches are great to have, but if you don't, your regular genoa winches will work just fine.
Your turning blocks must be attached to a sturdy deck fitting. A toe rail is perfect. If you don't have a toe rail that will work for this purpose, install a pad eye or other strong hardware with a backing plate.