Leeward runs a live pressure field over your fleet and re-solves every voyage as it moves. The same chart your master reads, resolved to a heading.
Every system on the chart is a vortex with a radius, a spin and a strength. Advect a ship through the sum of them and you have the route. The chart above is drawing exactly that.
Lows spin one way and draw air in, highs spin the other and push it out. Radius and strength come off the pressure chart; nothing is hand-tuned per voyage.
Each ship is a particle with a fuel curve and a laycan. We step it through the field, the way the chart steps its 14,000 particles, and keep the tracks that arrive on time.
Six-minute cadence. When a system deepens, the route changes with it, and the bridge gets a heading instead of a 40-page routing advice.
Each solve prints to a single advisory sheet sized for a 40 kB attachment over Inmarsat. Positions, courses and speeds the officer of the watch can steer, with the wind and pressure the solver saw at each one.
Colour is wind on the leg, on the same scale as the legend under the chart. Delta is against the great-circle plan the charterer signed.
| Vessel | Leg | Agent | Wind on route, 24 h | ETA delta |
|---|
Post the plan, get back a track: waypoints, the field each one was solved against, and the fuel curve that picked it. Everything on the bridge sheet is in the response.
# solve a voyage against the live field POST https://api.leeward.example/v3/solve { "vessel": "IMO9421268", "depart": "ESALG", "arrive": "GRPIR", "speed_kt": 13.5, "preset": "mistral" } → 200 { "track": 64 waypoints, "eta": "2026-03-08T17:25Z", "fuel_mt": 318.4, "delta": "-7.2h vs great circle" }
No routing-advice fees, no per-call billing. A hull is under routing or it isn't.
$490
Per hull · month
$390
Per hull · month · from 8
Annual
Contract · SLA
We open a berth a week. Tell us the vessel and we'll route the next leg alongside your current provider, then show you both tracks.
Global pressure and wind at 0.25°, re-gridded onto our own vortex model every six minutes. The chart on this page runs the same model at demo scale, so you can see what the solver sees.
Both, and neither is the deliverable. The deliverable is a track: waypoints and speeds your bridge can steer, with the field that produced them attached so a master can argue with it.
API, email, or the one-page advisory sheet over Inmarsat, which fits in a 40 kB attachment. The board on this page is the same data, rendered for the office.
Every solve is stored with the field it used. When a system deepens faster than modelled, the re-solve arrives with a diff instead of a new PDF that quietly replaces the old one.