SAIL PLAN DIMENSIONS
Determine the Correct Rig Dimensions for Your Sails
When it comes to optimizing your boat's performance, one of the key factors is understanding your sail plan and how its dimensions affect the overall handling and efficiency of your vessel. The basic rig dimensions for a yacht are generally understood. However, there are some differences in how sailors describe these dimensions. At North Sails, we want to make sure everyone is on the same page, which is why we've put together this guide on how we define sail plan dimensions and how to measure them accurately. Whether you're a seasoned sailor or just getting started, knowing how to properly measure your sail plan is crucial for making informed decisions about sail choice and tuning. Let’s dive in!
I – Height of Foretriangle
Elevation of Forestay, measured down to elevation of main shrouds at sheer line.
J – Base of Foretriangle
Horizontal distance measured from front face of mast at deck to position of headstay at sheer line.
P – Mainsail Hoist
Elevation of upper mast band or maximum main halyard position, measured down to lower mast band or top of boom.
E- Mainsail Foot
Horizontal distance measured from aft face of mast at top of boom to boom band or maximum outhaul position.
Is – Height of Inner Foretriangle
Elevation of Forestay, measured down to elevation of main shrouds at sheer line.
Js – Base of Inner Foretriangle
Horizontal distance measured from front face of mast at deck to position of inner headstay at sheer line.
Py – Mizzen Mainsail Hoist
Elevation of upper mast band or maximum main halyard position, measured down to lower mast band or top of boom.
Ey – Mizzen Mainsail Foot
Horizontal distance measured from aft face of mizzen mast at top of boom to boom band or maximum outhaul position.
ISP – Elevation of Spinnaker Halyard
Measured down to elevation of main shrouds at sheer line.
SPL – Spinnaker Pole Length
Distance from the forward end of the mast to the point where the spinnaker pole attaches to the sail or to the pole’s furthest extension.
STL – Spinnaker Tack Length
Horizontal distance measured from front face of mast at deck, forward and horizontally to position of spinnaker tack attachment point.
