Sail a real race, on your local water.
I built a sailing simulator that runs in your browser. Four real Florida venues so far. The wind, the current and the coastline come from the actual place. You sail a single-handed dinghy against an AI fleet, from the five-minute gun to the finish.
Four real venuesSnapshots of real wind and current, soon connected to live weatherLeaderboards comingFree
If you race a Laser or an ILCA, this is your boat. The hull geometry, the sail plan and the control lines are modelled on it, and the physics are built to reproduce how that hull actually behaves. How it accelerates, how it heels, how it slides sideways when you get it wrong. No crew, no spinnaker, and famously tender. Everything that makes the boat fast also makes it want to tip over, which is the whole game.
Six controls, plus your own body weight. Roughly in the order they matter:
Your first race, I'd use the tiller, the mainsheet and hiking. That's what I use. The other four do genuinely change how the boat goes, but as long as you don't pick the strongest wind you'll be fine without them.
Drag the on-screen helm to steer. MAIN IN and EASE trim the sail; HIKE gets your weight out. Two-finger pinch zooms. The finer controls sit in a compact grid you can ignore at first.
Tap ▶ Start to begin the five-minute sequence, or tap Skip to jump straight to the one-minute gun and start racing almost immediately.
| Key | Does |
|---|---|
| ← → | Tiller (reversed: bow turns opposite) |
| W S | Mainsheet (trim in / ease) |
| E D | Vang (on / off) |
| R F | Cunningham (on / off) |
| Q A | Outhaul (flat / full) |
| Z X | Centreboard (down / up) |
| Shift (hold) | Hike out |
| + − , wheel | Zoom |
| ] [ | Scrub tide clock (forward / back in time) |
| , . | Wind speed − / + |
| ; ' | Wind veer (port / stbd) |
| Space | Start sequence |
| Enter | Skip to 1:00, again to the gun |
| Backspace | Reset course |
| 1 2 3 | Wind scenario |
| M | Minimap zoom |
| L | Learning / Pro mode |
| P | Mute / unmute audio |
| C | Cycle race course preset |
| T | Cycle AI difficulty (Easy/Med/Hard) |
Push the tiller right and the bow turns left, the way a real tiller works.
Each venue is built from the real coastline (OpenStreetMap), that location's observed wind climatology, and its real tidal current. I've done my best on the direction and the relative strength, and I could still be wrong. If it doesn't match the water you sail, tell me.
Orange Park, St. Johns River
Tannic brown river water and a wide, forgiving racecourse. The St. Johns is one of the few major American rivers that flows north, so the ebb carries you downstream toward Mayport and the flood pushes you back up. Current is gentle here, the mildest of the four, which makes Rudder the place to learn.
Winds: summer sea breeze ESE ~10 kn · winter frontal NW 18 kn · a light ENE day at 6.
Course: windward-leeward with a gate.
Ortega, St. Johns River
A little further down the river and slightly more current than Rudder. Same tannic water, same north-flowing ebb, a shade more bite. The southeasterly is the everyday summer breeze; the northwesterly arrives with a winter front and turns the day into a survival exercise.
Winds: SE 130° · NNW 330° · ENE 65°.
Course: windward-leeward with a gate.
Matanzas Bay and the Atlantic
The hard one. Estuarine water in the shadow of the Bridge of Lions, and by far the strongest current of the four. Strong enough that the leeward mark had to become a gate, because in testing a single mark was genuinely unroundable in that ebb. Get the current wrong here and you will not finish.
Three areas: the Bay Race in Matanzas Bay, Ocean Practice outside the inlet, and an Ocean Race in the open Atlantic. Offshore racing here is real. St. Augustine Race Week runs a dedicated Atlantic offshore division.
Winds: ESE 120° · NE 40° · SSW 190°.
Current: ebb sets north, flood south.
Lake Worth Lagoon, West Palm Beach
My first club. Which is why it's here, even though everything else is north-east Florida.
Clear blue coastal water and the lightest current of the four. The lagoon runs north–south and racing happens east of the Intracoastal channel, beside the shipping water, not in it. The default is a soft seven-knot summer southerly. A winter front swings it northwest at sixteen and changes the venue completely.
Three areas: the Lagoon Race, Inlet Practice near Peanut Island, and an offshore Ocean Race out through the Lake Worth Inlet, where the real easterly Atlantic sea breeze fills in.
Winds: S 175° at 7 kn (default) · NW 330° at 16 · E sea breeze offshore.
Current: ebb sets north toward the inlet, flood south.
Do you sail one of these? You know that water far better than I do, and I'd rather hear it from you than keep guessing. Tell me which way the current actually runs, or where I've put the course somewhere nobody would ever race.
Tell me about your water →A race starts with a five-minute countdown. 5, 4, 1, 0. You're not waiting around, you're jockeying for position so that when the gun fires you cross the line at full speed, on the tack you want, with clear air. People who know say this is most of a race. I believe them.
Cross early and you're OCS, On Course Side. You have to sail back below the line before you can start properly, which is expensive. I'm usually about ten seconds late. Occasionally I'm OCS. What you want is to be moving fast and arriving at the line as the gun goes.
In a hurry? Skip jumps you to the one-minute gun.
Every venue races a windward-leeward course. Beat upwind to a mark, turn, run back down, repeat. It's the standard racing course worldwide because it tests pointing ability and downwind speed.
Some venues use a gate at the bottom instead of a single leeward mark. Two marks you sail between, then round either one. Gates exist because in real current a single leeward mark can be brutally hard to round.
Low Point scoring. Your finishing place is your score, so 1st is 1 point, 2nd is 2, and lowest wins. Fail to finish (DNF, DNS or DSQ) and you score one more than the number of boats entered in the series, which is why finishing badly always beats not finishing. In a Vela2D race that's the four boats on the water, so the number comes out the same either way. Your elapsed time is recorded too, and that's what the share line quotes.
Every mark is rounded to port. You leave it on your left, so the whole course turns counterclockwise. The one exception is the right-hand mark of a leeward gate, which you round to starboard. That's the point of a gate. You pick a side and round it the way it faces. Round a mark the wrong way and the leg doesn't count, so you have to go back and do it again. The minimap shows which mark is next.
The rule of thumb is wide in, tight out. Approach a little wider than feels natural, then carve so you exit close to the mark already on your new course. I still do it the other way round more often than I'd like, and it costs me several boat lengths to leeward every time. On an upwind leg you pay for that the whole way.
Touching a mark (RRS 31). Hit a mark and you owe a One-Turn Penalty. A full 360° containing one genuine tack and one genuine gybe, in the same direction. Weaving back and forth doesn't count. This is the real penalty from the real rulebook (RRS 44.1 and 44.2).
Finishing with a penalty still owed is a DSQ. Do your turn when you get it.
OCS. Over the line at the gun, and you must return below it before starting.
Correct side, correct order. Miss a mark or round it the wrong way and the leg doesn't count.
The marks are really rounded. This one took me three tries to get right. A boat used to get credit for a mark by crossing the correct side of it, which meant you could sail straight past and the game would tick the leg off anyway. It doesn't any more. It runs the Sail the Course definition's own test, where the string representing your track, pulled taut, has to lie on the required side of the mark. Same test for me, same test for the AI.
The whole fleet finishes. There's a 48-race test matrix that runs every venue, every course and every wind, and all 48 races finish with all 192 boats finishing. No disqualifications and no retirements. Older builds used to leave the odd boat parked head to wind in light air with a dash next to its name, and that bothered me more than it probably should have.
You can foul the AI fleet, and they can foul you. Hulls have real extent now, so boats touch instead of passing through each other. The fleet sails to the same rules you do. Nobody gets a private version. A foul costs the boat that had to keep clear a Two-Turns Penalty (RRS 44.1, made the way 44.2 describes): two full 360s, each with a genuine tack and a genuine gybe, in the same direction. Same machinery as the mark-touch penalty above. Still owed at the finish and you're DSQ.
Here's what the game doesn't know yet, so you're not surprised by it mid-race.
The list gets shorter. Slowly.
The start is the only pre-race phase. No general recalls, no black flag, no shortened course. There's no pre-start tactics beyond the start itself.
Weather is realistic, but it isn't live. Each venue's wind comes from that location's observed climatology, and the tidal current is a modelled scenario you pick, not today's forecast. Connecting it to live weather is the plan. It isn't done.
No leaderboard, and nowhere to save a time. You sail a race, you get a time, and then it's gone. The simulation is deterministic so a verified board is possible, and I want it. It needs accounts, and I haven't built those either.
The rules gaps are listed above, and I'd rather they sat on the page than surprised you on the water.
Found something that looks wrong for the water you actually sail? That's the most useful thing you can send me.
Tell me what's wrong →I'm still learning to sail this boat myself, so treat this as notes rather than coaching. It's what the model rewards, and what I got wrong often enough to notice.
Sailed well upwind in about ten knots, this boat sits at roughly 10–15° of heel. Not on its ear. Too much heel costs you in a few ways at once. The hull shape gets less efficient, you slide sideways more, and the helm loads up so the rudder drags like a brake. If you're heeled a long way over and fighting the tiller, you aren't going fast. You're going sideways, slowly.
A puff hits and the boat lays over. Every time, in this sequence:
I did this backwards for a long time. Hike first, get overwhelmed, capsize with the sheet still cleated. Ease first. You can always trim back in. You can't un-capsize quickly.
Vang on tightens the leech: full power, top of the sail working hard. Vang off lets the top twist open and spill wind. Because the top of the sail has the longest lever over the boat, twisting it off dumps heeling moment far faster than it dumps drive. Vang on for power in flat water, vang off when you're overpowered.
Cunningham and outhaul both flatten the sail, which is what you want as the breeze builds. In light air, ease everything. A flat sail in five knots is a slow sail.
Roughly 45° either side of the wind is a no-go zone. To get upwind you beat, zigzagging through a series of tacks. The green and red tracks on the water show your close-hauled headings on each tack.
VMG is velocity made good. How fast you're actually closing on the mark, not how fast the water is going past. Point too high and you'll pinch. The boat feels fine, speed drops, VMG collapses. Foot off too far and you're quick but sailing a longer course. The fast groove is narrow, and VMG is the only number that tells you when you're in it.
In Learning mode the panel says the same thing in words. LUFFING when you're too high, IN THE GROOVE when you've got it, EASE when the sail is stalled from being sheeted too hard, and TRIM IN when it's too loose.
Moving water pushes you sideways whether you like it or not. If the ebb is setting north at a knot and a half, you have to aim above the mark to arrive at it. The SET and DRIFT readout on the wind rose tells you which way the water is going and how fast.
Current also decides tactics. Sailing against the tide? Get out of the main channel into the shallows where it runs weaker. Sailing with it? Stay in the deep water and take the free ride. This is the part I most want a local to tell me I've got wrong.
The layline is the line from which you can fetch the mark without another tack. Tack onto it too early and you sail extra distance for nothing. Sail past it and every metre beyond is waste. You want to arrive on the layline late, not early.