I’ve read that, in light airs, it is recommended that the main boom should be sheeted in a little more inboard.

What is the logic behind that and should there be a commensurate adjustment inboard on the jib boom?

The whole idea seems contrary to the “if in doubt let it out” principle.

David 

 

Edited July 24, 2025Jul 24 by David Norris

IMHO, boat speed is your friend in light airs and I adopt your "if in doubt let it out" principle

i think that Ian Vickers speaks to this in his set up guides and on the video you can find on You Tube which is a quite comprehensive review of set up.  he suggests bringing in the main from 8mm from the centre to 5mm in light airs if i remember properly he also suggests easing the jib out; clearly works for him but like others i do tend to follow the if in doubt let it out.  have promised myself to test this alternative approach.  and guess it is about what is light airs what is super light and what normal?  the link to the video is i know on Nigel Barrow's website.  

Many thanks!

I think that by sheeting in the main and letting out the jib, Ian is saying to open the slot a little. From memory, Ian does not increase the draft of the foot of the main, but may increase the draft of the jib a little.

I suggest other changes for light air. Ease the back stay so the mast comes up straight to put some draft into the main. This also reduces the tension on the forestay, which puts some roundness in the leading edge of the jib. Ease the luff tension on jib and main. Ease the mast ram and vang to allow a bit more twist in the main as the wind gradient effect is more pronounced in light airs. If you sail with tight shrouds, ease them off a bit as this also affects jib stay tension.

How you sail is important - sail the boat with the sails cracked off to build and maintain boat speed – this will increase apparent wind, and reduce leeway. Avoid trying too point high.

John

My thoughts are that In light airs you need more twist in the main, so to get the majority of the sail back to where it normally sits the boom must be sheeted in more.

That’s very helpful, John. There is no mast ram on a DF95, nor shrouds, but I understand the principles behind your comments, which coincide with advice I have received privately.

David