Topping Lift - Mainsail Trim - Light winds...

[2Wind]

Today, it was very light winds out on the bay - 3.5 to 5 kts. Not ideal conditions for my boat.

It was a fabulous day and as I was sailing solo without an agenda or timetable to consider, I busied myself trying to tease out every last bit of speed I could. I know, I've heard it all before, "Lagoons are not designed with speed in mind...." Anyway, I decided to try.

With a heavily roached 85sqm 8 batton main, made of relatively heavyweight Hydranet, I have found in the past that when there is little pressure in the sail by virtue of light wind, the top third of the sail effectively has a reverse twist due to the leach tension generated by the sail weight and the boom weight being in excess of the twisting moment of the light wind pressure. As you ease the main sheet, the boom moves upward and to leaward, but fails to really address the lack of twist. So you end up with either sheeting and positioning the traveller to optimize the top of the sail or alternatively you can optimize down low, but you can't have both!

Enter the topping lift! It was like one of those moments when you suddnely think you have come across something that all the world has known about for years and you're the last to find out! Maybe so, but I'm not so proud that I can't bare my sole on CF.

So I found that I could more precisely anchor (no boom "wander" as you get when loose sheeted) and position the boom in both vertical and horizontal axises. By adjusting the topping lift and tensioning against it with the mainsheet and in comjunction with the optimizing the traveller position I could achieve ideal trim for the lower half of the sail and by ensuring that the leach was not excessively tight by tensioning the toppinglift, I could also optimize the upper half.

Here is a picture of my instruments showing true wind speed and direction, the iPad GPS SOG and the tridata boat speed. In 4 kts of breeze, what I did was worth about 0.5 to 1.0 kt which, bearing in mind the slow pace, was a 25% gain.

Did I mention that I had fun too!