I've got an old Gaastra Manic 3.7 (about 2008) that I have rarely used but now want to use in my beginner stage of windfoiling. I have googled for downhaul guidelines, but without success. Does anyone have any rules of thumb about downhaul and outhaul settings? I use mostly Ezzys, partly because David Ezzy is so thorough in providing rigging indicators and guidelines. P.S. I have two 3.7m masts (which Gaastra recommend): an old Powerex 85% carbon RDM and a Simmer RDM 10 (100% prepreg carbon). Both are constant curve.

Its not that old so modern wavesail rigging will work. Downhaul til top two battens are behind the mast and the batten above the boom sits level with the front of the mast. Latter is most important, and you will see progressively that they change to being more behind the mast as you go up
Outhaul until it will only barely touch the boom in the middle when pushed down by hand - this is for a normal new school shape wave boom.

Those masts though, are what they reckon now. Prior to 2017 Gaastra was hard top, you might find way too floppy leech on those CC masts, so too gutless for your initially get up and go.

For wind foiling use less downhaul and more outhaul. Tight leach and not much shape works best for pumping onto the foil, especially when learning.

Below is the "mast selector" from 2011, as said above Gaastra were really hard-top at the time when that sail was produced:

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philn said..
For wind foiling use less downhaul and more outhaul. Tight leach and not much shape works best for pumping onto the foil, especially when learning.

It's good for pumping but if one is well-powered, I prefer "conventional" settings, ie more typical floppy leach and a touch more outhaul for foiling than finned boards. All this isn't going to be as critical for a 3.7 unless you are really powered up, though, e.g. winds around 25-30 kts. depending on your weight and foil wing.