When I purchased new sails for Terrapin, I also bought a spinnaker. The spinnaker is used for downwind sailing when the wind is between 90 and 180 degrees off the bow. Paradoxically dead downwind sailing or “a run” is generally one of the slowest points of sail, mainly because you are relying on your sails to be “pushed” by the wind directly behind them. Conventional main and jib are not really designed for this. Instead, conventional sails are designed to be a curved airfoil, like a vertical airplane wing. The wind passing over the front of the sail provides “forward lift” and propels the boat forward. In some cases, this can propel the boat faster than the wind speed as in the recent Americas Cup catamarans. The spinnaker is a large light balloon like sail that catches the maximum amount of wind from behind to improve downwind sailing performance. It is generally used for light wind of less than 15 knots.
The spinnaker is also somewhat tricky to rig and deploy and I had no experience with them other than reading and watching YouTube videos. We have been on several stretches of long downwind sailing on Terrapin during our recent cruise to the Keys and have been frustrated with the slow speed. Finally, one day I decided to test out the new spinnaker. I think I made every mistake in the book and paid the price. With Laura at the helm, I went to the bow and pulled the spinnaker out of the bow locker. It is in a rather large bag and pretty unwieldly. I hooked it up to a bridle that ran from one bow to the other with a shackle to attach to one of the lower corners of the spinnaker, called the tack. The other lower corner of the spinnaker is called the clew and is where you attach the sheet that runs to the cockpit on the leeward side and controls the shape of the sail. By adjusting both the bridle position side to side and the sheet, I can control the position of the spinnaker and the amount of “ballooning”, or so goes the theory. The spinnaker is in a sock about 40’ long and designed to be raised and unfurled in two steps: 1. Attach the head of the sail to the spinnaker halyard and hoist it up to the top of the mast. 2. Pull on another line running from a cuff around the bottom of the sock to the top of the spinnaker and then back down again. Pulling on this line raises the sock and allows the lightweight nylon spinnaker to unfurl and catch the wind. To douse the spinnaker, you pull the sock back down with the same line. So, I hooked up the tack and clew and raised the sock on the halyard. So far so good. Except that by the time I had done all this, the wind speed had increased to about 15k, gusting to 20. I should have stopped right there. Hindsight is 20/20, right? Well, I raised the sock and all hell broke loose. The sheet running to the cockpit wasn’t secured and came loose, allowing the spinnaker to flap uncontrollably in the strong wind. It started to wrap around the forestay where the genoa is rolled up on a roller furler. I had also left the two genoa sheets attached to the genoa and these quickly became tangled with the spinnaker lines. I tried to bring the sock down but it was jammed. I spent what seemed like an eternity trying to control this crazy flapping spinnaker, but it was probably about 10 minutes. I finally went to the mast and lowered the halyard lowering the whole mess to the trampoline. Exhausted.
- Don’t try to fly the spinnaker in wind stronger than 15 knots, at least until you have plenty of experience.
- Attach the sheet and tack more securely.
- Make absolutely sure the sock is free and clear of all lines and on the proper (leeward) side the forestay.
- Remove the genoa or jib sheets so there is no chance of getting tangled
- Clear the deck of all stuff, fenders, docklines, etc.
- Practice with raising the spinnaker at the dock before attempting to use it under sail.
Well, after digesting and re-enacting the scenario in my mind, I finally got the courage to try it again when we were sailing downwind in much lighter wind. This time it worked perfectly! What a good feeling to pull up the sock and see this beautiful sail catch the wind and feel the boat accelerate.