Weather Routing

WindMar v0.2.0 — Weather routing on a North Atlantic crossing (fuel-gain study)

slmar.co • June 14, 2026 • study + PDF

A factorial fuel-gain study on a Gibraltar–New York crossing for an MR tanker, plus a worked seasonal expectation — least-fuel routing over coupled wind, sea-state and current fields. The gain is about 2% of voyage fuel at the physics ceiling, concentrated in heavy weather; the great circle remains a strong baseline.

What Weather Routing Actually Buys

slmar.co • May 25, 2026 • study + PDF + interactive report

A geometry / seasonal-β / forecast-α decomposition of optimizer fuel-ROI across ocean regimes, under ERA5+GLORYS replay against a pre-registered protocol. The forecast-dependent component a real-time service adds is under 1% of fuel — and that is a hindcast upper bound.