Vela2D ▶ Play now

Vela2D

Sail a real race, on real water.

A browser sailing simulator built on four real Florida racecourses. The wind, the current and the coastline come from the actual venue — the sea breeze that fills in off Jacksonville, the ebb that runs north out of Matanzas Bay, the shoreline your club races off every Sunday. You sail a single-handed dinghy against an AI fleet, from the five-minute gun to the finish.

▶ Play now How it works ↓

Four venuesReal wind and tideFreeNo account needed

What you're sailing

A 4.2-metre single-handed racing dinghy: one 7-square-metre sail on an unstayed mast, no crew, no spinnaker, and famously tender. If you race a Laser or an ILCA you will recognise the feel immediately — same hull length, same sail area, same control lines. Everything that makes the boat fast also makes it want to tip over, which is the whole game.

You have six controls plus your own body weight, and they matter in roughly this order:

  • Tiller — steering.
  • Mainsheet — sail in or out. Your primary throttle and your primary brake.
  • Hiking — your body is the ballast. Leaning out is how you keep the boat flat.
  • Vang — pulls the boom down, tightening the leech. On = powered and tippy. (Class Rule 3(d) calls it the vang; the parts diagram also labels it the kicking strap.)
  • Cunningham — pulls the luff down, flattening the sail and dragging the draft forward. For breeze.
  • Outhaul — flattens the bottom of the sail. For breeze.
  • Centreboard — down for upwind grip, up a little downwind to reduce drag. (It lifts straight up rather than pivoting, but the class calls it the centreboard, so that's what we call it.)

If you're new: sail the first race with just the tiller, the mainsheet and hiking. The other four are refinements, and the boat sails perfectly well without touching them.

Controls

Desktop

Key Does
← →Tiller (reversed: bow turns opposite)
W SMainsheet (trim in / ease)
E DVang (on / off)
R FCunningham (on / off)
Q AOuthaul (flat / full)
Z XDaggerboard (down / up)
ShiftHike out (hold)
+ − wheelZoom
] [Scrub tide clock (forward / back in time)
, .Wind speed − / +
; 'Wind veer (port / stbd)
SpaceStart sequence
EnterSkip to 1:00, again to the gun
BackspaceReset course
1 2 3Wind scenario
MMinimap zoom
LLearning / Pro mode
PMute / unmute audio
CCycle race course preset
TCycle AI difficulty (Easy/Med/Hard)

Touch

An on-screen helm you drag, plus MAIN IN / EASE and HIKE as the primary buttons, with the fine controls in a compact grid. Two-finger pinch zooms.

The tiller is backwards. On purpose.

Push the tiller right and the bow turns left. That is not a bug — that is how a tiller works on every boat that has one, and every sailor reading this already has it in their hands. It takes about ninety seconds to stop thinking about it. If you'd rather not, the on-screen helm on touch devices is presented as a wheel and behaves the way you expect.

How a race works

The start

Racing 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. Getting this right is most of a race.

Cross the line early and you're OCS — On Course Side. The game will tell you. You have to sail back below the line before you can start properly, which is expensive. Most beginners are far too cautious and start ten seconds late; a few are far too aggressive and start OCS. Aim to be moving fast and arriving at the line as the gun goes.

In a hurry? Skip jumps you to the one-minute gun.

The course

Every venue races a windward-leeward course: beat upwind to a mark, turn, run back downwind, repeat. It's the standard racing course worldwide because it tests the two things that matter — pointing ability and downwind speed — and removes almost everything else.

Some venues use a gate at the bottom instead of a single leeward mark: two marks you sail between and round either one. Gates exist because in real current a single leeward mark can be brutally hard to round — which is exactly why St. Augustine and Palm Beach use one.

You must round every mark on the correct side and in the correct order. The minimap shows you which mark is next.

How you're scored

Low Point scoring, the standard system: your finishing place is your score, so 1st = 1 point, 2nd = 2, and lowest wins. Fail to finish — DNF, DNS or DSQ — and you score one more than the number of boats that started, which is why finishing badly always beats not finishing.

Your elapsed time is recorded too, and that's what the share line quotes.

Rounding a mark

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. Rounding tight-then-wide is the classic error: you finish the turn several boat lengths to leeward of where you should be, and on an upwind leg you pay for it the whole way.

The rules

What Vela2D enforces

The sim scores you against three real rules:

Touching a mark (RRS 31). Hit a mark and you owe a One-Turn Penalty — a full 360° that contains one genuine tack and one genuine gybe, in the same direction. Weaving back and forth doesn't count; the boat has to actually go through the wind and then actually gybe. This is the real penalty from the real rulebook (RRS 44.1 and 44.2), implemented properly.

Finishing with a penalty still owed = DSQ. Do your turn when you get it. Carrying it to the finish line disqualifies you.

OCS. Over the line at the gun, and you must return below the line before starting.

Correct side, correct order. Miss a mark or round it the wrong way and the leg doesn't count.

What real racing adds (and Vela2D does not simulate)

Be clear on this, because it's the honest limit of the simulation: Vela2D does not model right-of-way between boats. You cannot foul the AI fleet and they cannot foul you. There are no protests. On real water, these are the rules that govern every one of those encounters:

  • Rule 10 — opposite tacks. A port-tack boat keeps clear of a starboard-tack boat. This is the big one, and the reason "Starboard!" is the most-shouted word on a racecourse.
  • Rule 11 — same tack, overlapped. The windward boat keeps clear of the leeward boat.
  • Rule 12 — same tack, not overlapped. The boat clear astern keeps clear of the boat clear ahead.
  • Rule 13 — while tacking. A boat tacking keeps clear until she's on a close-hauled course.
  • Rule 18 — mark-room. Inside the three-hull-length zone at a mark, an overlapped inside boat is entitled to room to round it.

Learn these before you race for real. Vela2D will teach you boat handling, tactics, current and the start — it will not teach you the right-of-way rules, because it doesn't referee them.

Cite: World Sailing, Racing Rules of Sailing 2025–2028.

What isn't finished yet

This is an honest list. It gets shorter over time.

Right-of-way between boats isn't simulated. As above — no port/starboard, no windward/leeward, no mark-room, no protests. You can sail through the fleet and nothing happens. This is the biggest gap between Vela2D and a real race, and it's the next major piece of work. Modelling it properly means the AI fleet has to obey the rules too, not just you.

The AI fleet doesn't always complete the course. In the stronger current — St. Augustine especially, and in light air — a boat can get set past a mark, fail to register the rounding, and end up scored DNF. You'll see it as a boat marked "—" on the standings. Your own race is scored correctly and finishes normally; it's the AI's course-following that's imperfect in current. Being fixed.

The start is the only pre-race phase. No general recalls, no black flag, no individual recall signals beyond your own OCS. No shortened course, no abandonment.

One boat, one rig. One hull, one 7 m² sail plan — no smaller rigs, no other classes, no handicapping.

Weather is realistic, not live. Each venue's wind scenarios come from that location's observed climatology, and the tidal current is correct in direction and relative strength — but it's a modelled scenario you pick, not today's actual forecast. Live weather is on the roadmap.

If you find something that looks wrong for the water you actually sail, say so — that feedback is the most useful thing you can send.

How to actually go fast

Flat is fast

Sailed well upwind in about ten knots, this boat sits at roughly 10–15° of heel — not lying on its ear. Excess heel costs you three 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 are not going fast. You are going sideways, slowly.

Ease, hike, trim — in that order

A puff hits and the boat lays over. The response, every time, in this sequence:

  1. Ease the mainsheet. Instant, and it spills power immediately.
  2. Hike hard. Get your weight out.
  3. Trim back in as the boat comes back up.

Beginners do it backwards — they hike first, get overwhelmed, and capsize with the sheet still cleated. Ease first. You can always trim back in; you can't un-capsize quickly.

The vang is your gearbox

Vang on tightens the leech: full power, and the top of the sail works hard. Vang off lets the top of the sail twist open and spill wind. Because the top of the sail has the longest lever arm over the boat, twisting it off dumps heeling moment far faster than it dumps drive. That's the trade: vang on for power in flat water, vang off when you're overpowered and need to survive.

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.

You cannot sail straight upwind

Roughly 45° either side of the wind is a no-go zone. To get upwind you beat — zigzag in a series of tacks. The green and red tracks on the water show your close-hauled headings on each tack.

Watch VMG, not speed

VMG is velocity made good — how fast you're actually approaching the mark, as opposed to how fast the water is going past. Point too high and you'll pinch: the boat feels fine, the speed number drops, and the 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.

The coaching cues do the same job in words: LUFFING (too high), IN THE GROOVE (right), EASE — stalled (sheeted too hard), TRIM IN (sheeted too loose).

Respect the current

This is what makes these venues distinctive and it's the thing most simulators skip. Moving water pushes you sideways whether you like it or not. If the ebb is setting north at a knot and a half, you must 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. At St. Augustine this is not a subtlety — it's the whole race.

Don't overstand the layline

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 pure waste. Approaching the windward mark, aim to arrive on the layline late, not early.

Four real places

Each venue is built from the real coastline (OpenStreetMap), the venue's own observed wind climatology, and its real tidal current — correct in direction and in relative strength. Where the game scales something for playability, it's the magnitude, never the direction.

Rudder Club of Jacksonville

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 from the ESE around 10 knots · winter frontal northwesterly at 18 · a light ENE day at 6.

Course: windward-leeward with a gate.

Florida Yacht Club

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 north-westerly 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.

St. Augustine

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 venues — strong enough that the leeward mark had to become a gate, because a single mark was genuinely unroundable in that ebb. Get the current wrong here and you will not finish.

Three areas to sail: the Bay Race in Matanzas Bay, Ocean Practice for free sailing 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.

Palm Beach Sailing Club

Lake Worth Lagoon, West Palm Beach

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 to the 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, because out there the windward mark is open ocean instead of a barrier island.

Winds: S 175° at 7 knots (default) · NW 330° at 16 · E sea breeze offshore.

Current: ebb sets north toward the inlet, flood south.