Sailboat Racing Trim — Part 11

In Chapter 11 of his book Racing Trim, Bill Gladstone talks about spinnaker trim. The following post shows a short summary of that chapter.

 

When flying a spinnaker, remember that optimum true wind angle changes with wind speed.  The optimum ranges from somewhere around 140 – 145 degrees in light wind to 165 degrees in 14 knots.  At winds higher than that, steer directly for the mark.  However, planing boats and sport boats can benefit from sailing higher angles

 

There are three primary ways to adjust the trim of the spinnaker.  They are by adjusting the spinnaker pole, position of the clews, and tension or ease of the sheet.

  • Pole – As a starting point, the pole should be perpendicular to the wind.
  • Clews – Pole height should be adjusted so that the clews are even.
  • Sheet – The sheet should be eased and trimmed so that the to shoulder of the sail curls.  Let the curl start to form and then trim in a bit.  This should be adjusted constantly.

Sheet Trim

The spinnaker trimmer needs to constantly watch the sail and adjust sheet tension.  Feedback also needs to be given to the driver and guy trimmer about how much pressure is in the sail.  If the pole height is too low, the upper luff will cave in and the leech will spill open.  If the pole is too high, the luff will fall away and the leech will be closed.

Guy Trim

Watch spinnaker trim from the shoulder to the tack.  If the pole is too far back, the luff will go to leeward of the pole.  If the pole is too far forward, the shoulder of the sail will go out to windward.

Crew Weight

Have crew members stay forward and leeward in light winds.  Move crew members aft and to the high side as the wind builds.

Broaching

In a broach, Gladstone instructs us to dump the spinnaker halyard, re-pack it, and raise it again.  However, I have also been on boats that ease sheet and vang in a broach type situation.  Wind levels and situation on the boat will dictate which path will be most effective.

 

This is the eleventh in a series of posts based on Bill Gladstone’s book Racing TRIM from the North U. Series.  Periodically, I post about a chapter or two.  This will be my short summary of what I’ve read.  You can read the posts to get my abbreviated summary; or you could read through the books with me.  Your comments can help point out what you find most interesting, or even poke fun at what I do and don’t know.  If you are interested in getting this book, you can find it in the online store section of NorthU.com for $25.