SailEdge™ by SailrScience starts from your ORC certificate and keeps the certified polar as the baseline anchor. From there, the runtime resolves apparent wind, force balance, heel, resistance, and depower to explain where each sail comparison gains or gives up speed. This page explains how those deltas are derived and why they matter.
Explore Your Edge Read the walkthrough →Every SailEdge computation begins with an ORC certificate — your certified dimensions, rig geometry, sail inventory, displacement, rated stability, and the complete polar table produced by the official ORC VPP. That polar is the immutable floor. SailEdge never overrides it, never adjusts it, never second-guesses it.
The certificate defines what the boat can do in ideal conditions with the rated sail plan. Everything SailEdge adds is built on top of that baseline. Built on ORC, not around it.
Model identity (as of July 2026). SailEdge product line R9.x · physics release R14 · hull library: DSYHS — 52 Delft Systematic Yacht Hull Series reference geometries (IGES-derived), assigned by certificate best fit and shown for your review · crew righting moment on the ORC VPP CARM basis (2023 documentation). Product releases and physics releases are separate tracks.
How a delta is stated. Baseline and candidate configurations are solved by the same R14 runtime. The displayed candidate speed scales the certificate’s own cell speed by the square root of the computed thrust ratio, bounded and capped against the certified baseline — so the ORC polar stays the anchor and shared model bias cancels in the comparison. The full force balance, including yaw, rudder, and CE/CLR effects, is a SailEdge computation beyond the scope of the official ORC VPP — a SailEdge output, never an ORC rating or official ORC speed prediction.
ORC reports true wind speed at a 10-meter reference height. SailEdge takes that true wind vector and converts it to apparent wind at the sail plan — accounting for boat speed, heel angle, and leeway. The apparent wind speed and angle that arrive at each sail drive everything downstream: the forces, the loads, the balance.
Get the apparent wind wrong and every downstream delta is wrong with it. This conversion is the first thing the runtime resolves because both the baseline and the candidate have to be compared on the same physical footing.
Each sail in the plan — main, jib, genoa, spinnaker, code zero — gets its own force decomposition. Lift and drag coefficients are computed from the sail’s geometry and the apparent wind angle. Those coefficients produce the drive force (forward) and side force (heeling) that let the baseline sailplan and the candidate be compared at the same wind condition.
Sails don’t operate in isolation. When a headsail sits in the main’s wind shadow at tight angles, the model accounts for blanketing — the reduction in effective wind that the downstream sail actually sees. The shape of each foil matters too: aspect ratio, overlap, roach. Different sail shapes produce different force profiles at the same wind angle.
At the professional tier, loft-specific sail shapes feed directly into these coefficients. The generic geometry is replaced with measured cut-sheet data.
Aero forces drive the boat forward. Hydrodynamic forces resist that motion. The R14 runtime uses a boat-integrated DSYHS hull backbone — 52 Delft-series reference geometries, IGES-derived — grounded in ORC certificate data and approved boat-carried hydro fields. Upright hull resistance, heel influence, appendage resistance, sideforce/leeway, rudder interaction, and approved wave resistance are resolved as named hydro lanes where the boat data supports them.
Your boat’s resistance profile is unique. When a lane is authoritative, the model uses your boat’s carried data and the live R14 runtime for both sides of the comparison. When a lane is bounded or waiting on better input, SailEdge discloses that instead of pretending to know more than it does.
Drive force wants to push the boat forward. Side force wants to heel it over. Hull resistance wants to slow it down. The righting moment wants to stand it back up. Change the crew weight and righting moment shifts — the entire equilibrium recomputes. SailEdge solves for the equilibrium state that lets baseline and candidate sailplans be compared under the same wind condition — iteratively, not by lookup.
The runtime converges on a single deterministic answer for each wind condition and sail comparison. Same certificate, same sails, same conditions, same answer. No random variation, no Monte Carlo, no stochastic noise.
Tune the righting moment for form vs ballast stability. Form-stabilized hulls lose their waterplane advantage as heel builds — the model captures that rolloff.
Real sails don’t hold their designed shape in all conditions. As wind builds past the sail’s effective range, the crew depowers — and the model does too. SailEdge applies multiple independent depower effects, each one specific to the sail type and the condition that triggers it.
Reefing the main is not the same as easing the traveler. Furling a headsail is not the same as flattening it. Each depower mechanism changes the force profile differently — reducing drive, reducing heel, or both — and SailEdge tracks each effect separately.
The result is a depower model that behaves the way sails actually behave: progressively, sail-by-sail, with each mechanism doing its own work.
Once the runtime resolves equilibrium, the ORC polar remains the certified anchor for the comparison. SailEdge evaluates how a candidate sailplan behaves relative to that baseline at the same wind condition, with baseline-anchored speed guardrails, stability thresholds, and minimum-drive requirements keeping the comparison inside a qualified envelope.
Baseline stays untouched as the reference. Candidate upside is published only inside the allowed compare fence, and any blocked or unstable condition is reported as such instead of being passed off as a replacement certified speed. Every limit is attributed so you can see what bounded the answer and why.
The certificate is the contract. SailEdge publishes directional deltas from that contract, not official ORC speed changes.
The Edge Map is the output surface. Each cell is one wind condition (TWA and TWS), one baseline-versus-candidate sail comparison, and one published speed delta. The color encodes that delta. Tap a cell and the detail card opens.
What you see in that card depends on your tier — the decision layer shows the answer, the diagnosis layer shows the force balance, and deeper layers preserve the baseline, candidate, and delta correspondence. Three levels of depth. The compare semantics stay the same throughout.
Upload your ORC certificate. See where a sail change moves the boat relative to baseline.
Explore Your Edge Anatomy of a cell →