How the race is sailed

The boat

One polar for the whole fleet. Each race carries one class polar, the standard text table your routing software reads and writes: a header row of true wind speeds, one row per true wind angle. A performance factor (usually 90%) derates it to the speed a well-sailed boat actually makes. You can download the exact polar from every race page.

The boat steers itself toward your next waypoint. At every step it picks the heading that makes the best speed toward that waypoint (best VMC). A waypoint dead upwind or dead downwind is still reachable; the boat sails the tacking or gybing angle that gets there fastest and holds its position on the line to the waypoint.

Tacks and gybes cost time. The boat holds its tack until the other is clearly faster (about 3% better), then crosses the wind and stands still for the race's manoeuvre penalty, typically 90 to 120 seconds. The count of tacks and gybes shows in your boat panel.

The weather

Real wind, in near-real time. Wind at 10 m comes from Open-Meteo, hourly, on a 0.25° grid, interpolated between hours. The engine evaluates each boat with the wind that was actually forecast for that hour, so nobody, the server included, knows the future.

Current sets the fleet. Where a race has currents on, real surface current from the same source pushes every boat, sailing or parked, for the whole step.

Ten-minute steps. Boats advance every few minutes (the race page says how many) whether or not anyone is watching. Each step is written to a public track.

The forecast you sail is the forecast you get. Every six hours the server saves the wind forecast over the race area as a GRIB file. Download it from the race page into qtVlm, Expedition or XyGrib and route with exactly what was known at the time.

If the weather feed goes down, the boats keep sailing on placeholder wind, the race page shows a warning, and route submissions pause until real data is back, so nobody can route against invented weather. The committee log records when it happened and when it recovered.

The course

Marks and the mark radius. A race is a list of marks: start, roundings, finish. A boat passes a mark when its path comes within the race's mark radius (usually 2 nm) of it. Some marks must be left to port or to starboard, and the race page says which.

Your route is reconciled with the course when you submit it. Routing software rarely lands exactly on our marks. Waypoints you are already standing on are skipped. Where your route never comes within the mark radius of a required mark, the mark is inserted at the closest approach. A pass on the wrong side of a sided mark, or straight over it, is rebuilt as a rounding on the correct side. Every adjustment is reported back to you. You always sail the real course; there is nothing to gain by cutting a mark and no disqualification when your finish line sits half a mile from ours.

Exclusion zones drag. Traffic separation schemes, ice limits and wildlife zones are drawn red on the chart. A boat inside one sails at half speed. Inside is always slower than around.

Shallow water drags too. Real bathymetry is checked every step. In less water than the race's grounding depth (usually 15 ft) the boat drags through at half speed. There is no land avoidance: a route across a headland will try to sail it, slowly, so route around land like you would offshore.

Changing your route

Only the future changes. When you submit a new route, the boat is first sailed up to now under the old one. Everything sailed is locked; only waypoints not yet reached are replaced. Time never rewinds.

The practice course never closes. Between real races there is always a rolling-start edition of Newport to Bermuda on the board: enter any time, and your boat leaves the line the moment you submit a route. Finishers rank by their own elapsed time, so when you started does not matter. Each edition takes entries for four weeks; the next opens itself.

Real races: entries close at the scheduled start. Enter before it and submit a route by then; the boat waits on the line and the engine sends it off with the fleet. That holds even when the real fleet is postponed: entries still close at the published time, and the virtual boats simply wait longer on the line. A boat entered without a route by the scheduled start is given the straight-line course, every mark in order to the finish with the sided ones rounded correctly, and its navigator can take over at any time. Once under way, a boat that runs out of route parks at its last position and waits for the next one.

Virtual boats start when the real fleet does. In a race with a tracked real fleet, boats wait on the line until 5% of the real boats have been seen under way after the gun, then start from that moment. A postponed or delayed start holds the virtual fleet with it.

Every submission is timestamped. Your profile shows when each route arrived and how many waypoints it carried. That log is public; the waypoints themselves are not.

Penalties

None of them disqualify you and none shorten the course. In full:

• Each tack or gybe: the race's manoeuvre penalty, in seconds of stopped time.
• Each step inside an exclusion zone: half speed.
• Each step in water shallower than the grounding depth: half speed.
• A route that misses a mark: the mark is inserted into your route, so you sail to it.
• A route that passes a sided mark the wrong way: rebuilt as a rounding on the correct side.

Admin actions

Race committees correct things, and so do the admins here: a mark placed wrongly, a start postponed, a zone added from the sailing instructions, a bad weather fetch. Every such change goes on the race page's race log with when and why.

A restart means an admin re-sailed a boat from the gun, through the recorded wind, on its latest route. It is how a boat is made whole after a correction; nobody gains or loses from it.

What is public

Your sailed track, your position, your tacks and groundings, and the times you submitted routes are public, like any race tracker. Your future waypoints are private to you. An account is a username, a display name and a password hash, and an email address. The address is where password-reset links and notices about your races are sent; other navigators never see it.

Your navigation software

Plain text formats throughout, so anything works. qtVlm is free; Expedition, Adrena, TimeZero, LuckGrib, OpenCPN and PredictWind all read and write the same files.

Getting the polar in

Each race page offers the polar as a .pol text file (TWA rows, TWS columns). Apply the race performance factor so your routing matches how the boat sails here.

Getting the course in

Every race page offers the marks as a GPX route. Import it, route between the marks with the race GRIBs, and upload the result.

Getting your route out

Export your route as GPX, or as CSV with lat and lon columns, and upload it on the race page. You see it on the chart before it replaces anything. Only the waypoints matter: your boat sails them in order at polar speed through real wind.

Getting your track back

Download your sailed track as GPX from the race page and overlay it on the GRIBs in your software to see where your routing gained or lost. Your current position is also a one-waypoint GPX: import it as the departure point for the next routing run.