Draft too far forward?

Discussion in 'Sail Trim with Don Guillette' started by danstanford, Sep 13, 2018. Add this thread to a FAQ

  1. danstanford

    danstanford

    Joined Aug 2, 2010
    270 posts, 41 likes
    Beneteau 323
    CA Cobourg
    We are the boat in the extreme left of this shot taken shortly after the start. I thought the shadow on the luff of our jib looked odd and am wondering if I had the halyard tension too high for the conditions? It certainly looks like we have much less draft than the other boats in the shot.
    I am not sure what night this was taken but it looks like 10 knots or so to me and we are close hauled.
    Thoughts and observations?
    Thanks, Dan
     

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  2. JRacer

    JRacer

    Joined Aug 9, 2011
    954 posts, 351 likes
    Beneteau 310
    US Cheney KS (Wichita)
    Pretty hard to tell without looking or a pic shot from the deck directly beneath the sail. In general, jibs deepest draft should be about 30-35 percent aft of the luff. Yes, you are correct that a halyard too tight would pull it forward.
     


  3. thinwater

    thinwater

    Joined Mar 26, 2011
    2,344 posts, 572 likes
    Corsair F-24 MK I
    US Deale, MD
    The best bet is to add some draft stripes and take pics while lying on your back, looking up. Shadows can be misleading.

    The best location will change with conditions.
     


  4. danstanford

    danstanford

    Joined Aug 2, 2010
    270 posts, 41 likes
    Beneteau 323
    CA Cobourg
    JR, that sail has no draft stripe but I have not noticed it looking odd when driving. I would say we have been struggling to point with some of the other boats though upwind speed seems OK...we always want more, right?
    For sure that photo and a couple of others make it look like the deepest draft is way forward at least in the top of the sail.
    Dan
     


  5. Jackdaw

    Jackdaw

    Joined Nov 8, 2010
    10,437 posts, 3,437 likes
    Beneteau First 36.7 & 260
    US Minneapolis MN & Bayfield WI
    The lower 1/3 of the sail looks fine. I'm betting your jib car is too far back.
     


  6. danstanford

    danstanford

    Joined Aug 2, 2010
    270 posts, 41 likes
    Beneteau 323
    CA Cobourg
    In light airs last night I did move the cars up and picked up some speed. This sail is new this spring and we have been wrestling with the car position by trying to get the telltales to break evenly but ignoring the fact that it looks to flat in the lower portion and not flat enough in the upper.
    We keep learning because you folks keep taking the time to help us, thanks.
     


  7. Jackdaw

    Jackdaw

    Joined Nov 8, 2010
    10,437 posts, 3,437 likes
    Beneteau First 36.7 & 260
    US Minneapolis MN & Bayfield WI
    Indeed, good sail shape is is a very complex interactions, and frankly jibs are the hardest to get right. Their very high-aspect nature makes this this way. At the end of the day, the key is figuring out what is fastest. For sure look at your hali tension as well. As you have found, these setups will differ dependent on windspeed. Mark your cars and halyards, and start keeping track. We have rulers on the deck to note the marks on the halyards, which are whipping twine. On the Beneteaus we used a Fein tool to remove the nubby anti-skid where the rulers are stuck. They would not stay attached otherwise.

    2502A841-F885-49E2-982B-9FF2B3D7A951.jpeg
     




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