New FastSeas Routing Engine

22 October 2026

FastSeas has a new routing engine. It is built to handle hard routes: complex coastlines, archipelagos, and weather that changes along the way. It uses the finest global grids the public weather models publish: 0.25 degrees for wind and waves, and 1/12 degree for ocean currents. And it steps through time as finely as each model allows.

New Routing Model Features

NOAA GFS wind, 0.25 degrees. Hourly for the first five days, then every 3 hours out to 16 days.
ECMWF wind, 0.25 degrees. Every 3 hours for the first six days, then every 6 hours out to 15 days.
NOAA RTOFS ocean currents, 1/12 degree (about 0.08 degrees, or 5 miles).
NOAA GFS-Wave (WAVEWATCH III) waves, 0.25 degrees.
ECMWF waves, 0.25 degrees.
Wind, current and waves all act on your boat. The router weighs all three at every step.
Land avoidance that copes with hard coastlines, including fairways through dense archipelagos.
Global coverage.
Your comfort and safety limits respected. Set the most wind and the roughest sea you are willing to sail in, and the route keeps within them, waiting where it has to.
Notable events along the route, such as thunderstorm risk, squall conditions, heavy rain, and rough or dangerous seas.
Polars for monohulls, catamarans and trimarans, from light to heavy.
Optional waypoints along a route.
A route in seconds. On our users' own routes of 350-650 miles, the calculation takes 2 seconds at the median, and 9 in 10 finish within 3 seconds on GFS and 5.5 seconds on ECMWF. Routes of 650-1,500 miles take 3-4 seconds at the median. Your wait adds a moment for the queue and the page.
Weather at every point along the route: wind and gusts, current, the sea (height, period and direction), air temperature, cloud cover, rain, and CAPE (the energy available to thunderstorms).
Motoring by your settings. The route motors when the wind is too light by your rules, and your motoring speed slows in the wind and sea it meets.

Fifteen Classic Courses

A router is easy to show on an easy route. So we sailed the new engine on fifteen classic courses: ocean races, famous passages, and a few that are hard for any router. Among them are the Transpac, the Sydney Hobart, the Chicago Mac, the Newport Bermuda, Cape Town to St Helena, and Cape Town to Melbourne across the Southern Ocean.

Each course starts and finishes a few miles off its harbour, in open water. Each was sailed on both forecast models, GFS and ECMWF, at three departure times a day apart, with ocean currents and waves on and no motoring. That is 90 routes.

All 90 arrived. Every course, on both models, at every departure.

Three boats sailed them, each from a published polar:

TP52 and First 40.7: from the ORC's 2024 certificates, the middle-rated boat of each class.
Volvo 70, on four of the long courses: a Volvo Open 70's published polar.

The hours below are the middle of the three departures on each model. They come from one week's forecasts, so they are this week's weather, not a passage's typical time. The polars also stop at 20-24 knots of wind and are held flat above that, so hours in stronger winds are a little quick. Calc time is how long each route took to calculate, from its fastest to its slowest run.

Course	Boat	GFS: miles sailed	GFS: hours	ECMWF: miles sailed	ECMWF: hours	Calc time
Cape Verde to Barbados	Volvo 70	2,246	180	2,216	172	8-10 s
Cape Town to Melbourne	Volvo 70	5,713	365*	5,738	361*	17-41 s
The Hague to Genoa, through Gibraltar	Volvo 70	2,475	277	2,541	238	9-12 s
Alicante to Cape Verde	Volvo 70	2,068	184	2,096	175	7-8 s
Transpac: Los Angeles to Honolulu	TP52	2,564	224	2,543	225	7-10 s
Heraklion to Palma de Mallorca	TP52	1,241	152	1,211	142	4-6 s
Chicago Mac: Chicago to Mackinac Island	TP52	303	42	303	36	0.7-0.9 s
Sydney Hobart	TP52	633	45	639	49	1.6-2 s
Mangonui to Stewart Island	TP52	978	94	999	96	3-4 s
Newport Bermuda	First 40.7	652	65	653	64	2-2.5 s
La Rochelle to Las Palmas	First 40.7	1,397	192	1,426	219	7-8 s
Manila to Davao	First 40.7	845	145	848	163	8-11 s
Cape Town to St Helena	First 40.7	1,846	232	1,850	231	7-8 s
Sydney to Auckland's west coast	First 40.7	1,157	125	1,150	131	4 s
Cork to La Coruña	First 40.7	500	55	505	58	1.4-1.5 s

* Cape Town to Melbourne takes about as long as the forecasts reach. GFS runs out at 16 days and ECMWF at 15, and this passage takes 15-16 days. On five of its six runs the last part was sailed on the forecast's final hour, held. So read it as proof that the route arrives, and take its hours with a pinch of salt.

Some of these courses are hard for a router. Manila to Davao threads through the islands of the Philippines: the route sails about 850 miles for a course 554 miles apart in a straight line. Mangonui to Stewart Island is free to go down either side of New Zealand. And The Hague to Genoa has to find its way round Spain and Portugal and through the Strait of Gibraltar.

We should be honest about where we started. The FastSeas of 2020, routing on 1-degree GFS wind alone, failed three of these fifteen courses: The Hague to Genoa, Mangonui to Stewart Island, and Manila to Davao. Today all three arrive, on both models.

Sample Route: The Hague to Genoa

A wind map of western Europe, coloured from blue (light wind) to red (strong), with two sailing routes from The Hague, in the Netherlands, to Genoa, one orange and one red. Both run south down the Channel and the Bay of Biscay, round Portugal and through the Strait of Gibraltar, then across the western Mediterranean to Genoa. A blue straight line joins the start and the finish, and a readout beside Spain gives the boat's position, wind and speed at that time. — The Hague to Genoa on the new engine, a Volvo 70 departing Thu 22 Oct 12:00 AM UTC: the orange line is the ECMWF route and the red line the GFS route, over the ECMWF 20 Oct 18z wind forecast for about 8:00 AM UTC on Thu 29 Oct. The readout is the boat's position, wind and speed on the route at that time.

This is one of the hardest of the fifteen for a router. The start is off Scheveningen, The Hague's harbour, in the North Sea. The finish is off Genoa, at the top of the Mediterranean. Between them lie the whole of Spain and Portugal, and one way through: the Strait of Gibraltar, under 8 miles wide at its narrowest. The course has a waypoint in the middle of the strait, so the route must pass through it.

The route has to get round a lot of coastline, through a narrow gap, and across two very different seas: the Atlantic first, then the Mediterranean.

The Overview tab for The Hague to Genoa on ECMWF, departing Thu 22 Oct 12:00 AM UTC. Six figures: passage 11 days 5 hours, distance 2,669.3 nautical miles, average speed 10.2 knots, maximum wind 40 knots, maximum gust 59 knots, and 0 hours of motoring. Below them, the warnings along the way, each with its dates: the boat hove to and drifting downwind for 2 hours, with a suggestion to wait in port instead and a Plan this departure button, hove to again for an hour, a severe sea for 3 hours, a hold for the sea to ease, moderate rain, and rain over the passage. — The route's Overview tab: the passage at a glance and the warnings along the way (left), then its wind, boat speed, sea and weather charts (right). This is the ECMWF route of a Volvo 70, departing Thu 22 Oct 12:00 AM UTC on the ECMWF 20 Oct 18z run. Unlike the runs in the table, it was planned with limits: a maximum wind of 60 knots (wind or gust) and a maximum sea state of Very rough. The boat hove to between Cherbourg and Weymouth to meet them, and sailed 2,669 miles in 11 days 5 hours.

The same Overview tab scrolled to its charts: wind and gusts in knots, peaking at a gust of 59 near the start against a dashed gust limit line at 60, then boat speed, and colour bands across the passage for sea state, air temperature, cloud, rain and CAPE. Below them, a table of the share of the passage sailed in each wind range and point of sail. — The route's Overview tab: the passage at a glance and the warnings along the way (left), then its wind, boat speed, sea and weather charts (right). This is the ECMWF route of a Volvo 70, departing Thu 22 Oct 12:00 AM UTC on the ECMWF 20 Oct 18z run. Unlike the runs in the table, it was planned with limits: a maximum wind of 60 knots (wind or gust) and a maximum sea state of Very rough. The boat hove to between Cherbourg and Weymouth to meet them, and sailed 2,669 miles in 11 days 5 hours.

On this week's weather, the Volvo 70 sailed 2,441-2,580 miles, taking 231-281 hours, or 10-12 days. Each route took 9-12 seconds to calculate.

The two models did not agree. On GFS the middle of the three times was 277 hours; on ECMWF, 238, about a day and a half less. That is a good reason to look at both before you go: run the same route on GFS and on ECMWF, and compare.

The Positions tab for The Hague to Genoa, a table of the route's first six points from the start at 52°9.0'N 4°3.0'E on Thu 22 Oct at 12:00 AM UTC. Each row gives the position, heading, speed, course and speed over the ground, wind speed, gusts and direction, true wind angle, ocean current speed and direction, air temperature, cloud cover, rain, CAPE, the sea's height, period and direction, its sea state level (Very rough, then Rough and Very rough again) and the speed lost to the sea. — The route's Positions tab, here its first six points: each row carries the wind, current, sea, rain and CAPE at that point.

Every point along the route carries its weather: the wind and gusts, the current, the sea's height, period and direction, the rain, and CAPE for thunderstorm risk. You can see where the hard parts of the passage are, and when you will meet them.

Sample Route: Manila to Davao

A wind map of the Philippines with two sailing routes from Manila to Davao, one pink and one yellow, and a blue straight line between the two. Both routes leave Manila Bay and run south down the western side of the islands, then round the south-west tip of Mindanao at Zamboanga and east along its south coast to Davao, well clear of the blue line. A readout beside the eastern, pink route gives the boat's position, wind and speed at that time. — Manila to Davao on the new engine, a First 40.7 departing Tue 27 Oct 4:00 AM UTC: the pink line is the GFS route and the yellow line the ECMWF route, over the GFS 20 Oct 18z wind forecast for about 9:00 PM UTC on Thu 29 Oct. The readout is the GFS boat's position, wind and speed at that time. Both go down the western side of the islands and round Mindanao's south-west tip, not straight across them.

Manila and Davao are 554 miles apart in a straight line, with the islands of the Philippines in between. The route has to find a way through them, among narrow passages and headlands.

The First 40.7 sailed 821-865 miles over the six runs, taking 130-181 hours. The middle departure took 145 hours on GFS and 163 on ECMWF. Each route took 8-11 seconds to calculate.

When you leave matters here. On GFS, leaving two days later added more than two days: 130 hours from the first departure, 181 from the last.