Downhaul under spinnaker

Hey everyone,

Do you release your main downhaul when under spinnaker? This seems to be a common recommendation and the Nacra Infusion manual says so as well: http://www.microwindracing.com/boat.html (table down the bottom, I think it’s some kind of extract but it looks official ).

Interestingly Capricorn manual recommends the „same“ settings as upwind: https://www.manualslib.com/manual/750751/Ahpc-Capricorn-F18.html?page=34#manual

Any ideas why that is?

Cheers

It depends on how tight the down haul was when going upwind, and what the apparent wind will be once the spinnaker is up. If it was very tight going upwind and you’ll be going very deep downwind, ease it to gets a deeper draft into the main, just remember to tighten it again at the C mark before you turn upwind again.

The goal is to maintain an optimum mainsail shape, usually flatter going upwind and fuller going downwind.

Thanks Timbo! The Infusion manual says “off” though, which sounds like “release completely”?

Here’s the different downwind Cunningham settings for different wind speeds (I’ve also found the C2 manual):

Infusion
< 6 knots: light - no wrinkles
6 to 9 knots: off
> 9 knots: off

Capricorn
1 to 5 knots: just no horizontal wrinkles
6 to 15 knots: light to hard
> 15 knots: extremely hard

C2
1 to 5 knots: just remove wrinkles
6 to 15 knots: off
> 15 knots: off

So what I’m wondering is, why does the Capricorn manual recommend different settings compared to the other boats in medium and strong winds?

Capricorn settings above look like upwind settings. Heavy Cunningham/downhall downwind with the spinnaker up in big breeze is an invitation for a folded mast. Releasing rotation and Cunningham, and keeping main sheet tension on are the three things that protect the mast above the hounds.

Thanks Jeff! It's probably just a typo in the manual then!