International Moth


Upwind Technique

  • More vang improves VMG upwind.  With a 32:1 you should need moderate tension once up and foiling and very tight tension upwind once fully powered up.
  • Reduce Vang for a little more power when needed.
  • Once fully powered up, i.e. TWS greater than 12-14kts max vang.
  • Downhaul should be always snug to remove creases and then increased slowly with windspeed and power requirements - Vang sheet the sail as opposed to cunningham first as primary power control.
  • Once fully overpowered upwind max vang and cunningham, as much as the sail will allow on cams etc. there may be a requirement to ease some vang upwind when very windy.
  • Set the outhaul tight ashore once the vang is on and 1/3 cunningham.
  • Shroud tension should be just taught when rigged ashore.

    Downwind Technique

    • Vang eased but not too much.  Overeasing causes the head to wtist open too much.
    • C-Ham eased till there are just wrinkles on luff in light wind, a little less in breeze.
    • No need to adjust outhaul as easing the cunningham has the effect of deepening the base sufficiently.

    Good Luck on the Water!

    Contact the International Moth Experts:

    Ruairidh Scott

    +44 (0) 1329 443 430 Work


    ruairidh@od.northsails.com