Sail Smarter Race Analytics (build 43)
J70 Corinthian Worlds Race 6 — Saturday, May 30, 2026
Data Analytics

Race window

Started 10:50 AM — showing 5.00 min pre-start plus 1h 37m of racing.

Manually cut the race off at a finish time — anything logged after it is ignored everywhere below (stats, charts, everything).

Start analysis

Based on the start line position logged by your instrument and the moment your track actually crosses it.

Start replay

Watch the approach and the gun. The readout shows distance to the line, the countdown, and time to burn — the surplus between the two — second by second.

0.00 m20.52 m41.03 m61.55 m82.06 m102.58 m123.09 m143.61 m164.12 mPin ★ favouredRC boatTWD197°steady
T−60s
0.90 kts  ·  41.1 m to the line  ·  60s to the gun
Ladder linesturning about the next mark, averaged over 10s

Race replays

The whole race, the start, each leg and each mark rounding, played back on a wind-up map. Pick one and press play — the boat is drawn at its real heading, at real elapsed race time. Individual tacks and gybes have their own overlaid traces further down, which say more about a turn than watching it does.

0.00 m403.53 m807.07 m1210.60 m1614.13 m2017.67 m2421.20 m2824.74 m3228.27 mTWD197°−10°
T+0s
3.50 kts  ·  158°  ·  39° TWA  ·  2.71 kts VMG upwind  ·  6.5° heel
Ladder linesturning about the next mark, averaged over 10s

Start line bias

Wind-up view of the line itself, from the pin/RC-boat position your instrument logged — which end was favoured, and how much of that advantage you actually used from where you started.

Wind

Estimated (high confidence)

Across 19 tacks, your settled headings average 251° and 159° — 92° apart — which puts the wind at 205° (high confidence). That's 5° anticlockwise of the 209° in use. Apply it if the breeze was steady; leave it if it genuinely shifted during the session.

Which wind to analyse against

A boat sailing a settled straight line is a wind vane: its heading sits half its own tacking angle to one side of the wind (half its gybing angle either side of dead downwind). Turns, and the seconds either side of them, are left out, as is the minute around every mark rounding. Live is the default, because a wind that moved is better described by a wind that moves — switch to fixed to use one direction throughout.

Reading the wind off your own track over 91 min, averaging 207° and swinging 34° across the race. One boat is one wind vane, so treat this as a good guide rather than an instrument — the fleet tools average the same reading across every boat in the race.

The wind through the race

Wind direction read off your own straight-line sailing, minute by minute. The dashed line is the race average (207°); the axis is labelled in real bearings. Total swing across the race: 34°.

192°197°202°207°212°217°222°10:50 AM11:12 AM11:35 AM11:58 AM12:20 PM

Ticks along the bottom are your tacks and gybes.

Speedo calibration (STW)

Corrects a speedo skew between tacks (positive = port reads faster), upwind and downwind separately. Applies to STW only, feeding every STW figure below. "Auto-calculate" sets both from your port/starboard averages.

Track

Scroll to zoom · drag to pan · hover for details
Open this area in OpenStreetMap ↗

Tide (SOG vs STW)

Colours the track by the SOG-vs-STW gap — green where current helps, red where it holds you back. Purple arrows show estimated current direction and strength, averaged per patch of track with enough data.

Fewer patches: smoother, more confident arrows but less detail. More patches: finer detail, but patches with too little data won't show an arrow.

A boat slides to leeward of where it points, and the slide reverses with the tack — left in, it is a current that flips every time you tack. Compass deviation does not reverse, which is what tells the two apart. Both affect the tide only.

What the tide was worth, leg by leg

The current at each fix, projected onto the bearing from where you were to the mark you were sailing for, added up over the leg. Positive means the water carried you toward the mark; negative means you had to sail through it. "Across" is how hard it was setting you off the direct line — neither a gain nor a loss, but the reason a leg can feel like a shift when it isn't one.

LegTide toward the markWorthAcross the courseAverage current
Upwind 1−304 m−1m 56s88 m right0.42 kts setting 355°
Downwind 1+166 m+55s119 m right0.38 kts setting 52°
Upwind 2−93 m−40s247 m right0.33 kts setting 355°
Downwind 2+215 m+1m 25s373 m right0.53 kts setting 55°
Whole race−16 m−16s

Worked out from the gap between your GPS speed and your speed through the water, so it is only as good as your speedo calibration — a paddlewheel reading a few per cent off shows up here as current. Leeway isn't modelled either, which puts a little phantom current to leeward.

Scroll to zoom · drag to pan · hover for details

Boat speed

Heading & manoeuvres

Polar — speed (SOG) by wind angle

Upwind leg comparison

Windward legs between tacks, compared on boat speed and heel angle.

Leg Time Tack Duration Distance Avg speed (SOG) Max speed (SOG) Avg speed (STW) Max speed (STW) VMG Avg heel Max heel Avg heading Wind angle

Upwind leg by leg breakdown

Each upwind leg mark to mark (not tack to tack), one column per leg in race order.

Downwind leg by leg breakdown

Each downwind leg mark to mark (not tack to tack), one column per leg in race order.

Tack comparison (±30s)

Manoeuvre instantDarker = further made good

Every tack, aligned and rotated so "up" is toward the wind — overlaid to compare distance made good, ranked best to worst. Row numbers match the "#" column in the table below. Tacks missing the full before/after window are excluded.

-50m0m50m-50m0m50mtoward wind ↑#7 · new tack Starboard — made good +66.59 m (rank 1)#7 — made good +66.59 m (rank 1)1#5 · new tack Starboard — made good +59.51 m (rank 2)#5 — made good +59.51 m (rank 2)2#20 · new tack Starboard — made good +59.18 m (rank 3)#20 — made good +59.18 m (rank 3)3#9 · new tack Starboard — made good +55.47 m (rank 4)#9 — made good +55.47 m (rank 4)4#8 · new tack Port — made good +52.91 m (rank 5)#8 — made good +52.91 m (rank 5)5#6 · new tack Port — made good +51.96 m (rank 6)#6 — made good +51.96 m (rank 6)6#21 · new tack Port — made good +49.82 m (rank 7)#21 — made good +49.82 m (rank 7)7#18 · new tack Starboard — made good +47.43 m (rank 8)#18 — made good +47.43 m (rank 8)8#17 · new tack Port — made good +45.42 m (rank 9)#17 — made good +45.42 m (rank 9)9#22 · new tack Starboard — made good +45.28 m (rank 10)#22 — made good +45.28 m (rank 10)10The manoeuvre itself (t = 0)
Rank # Time New tack Made good Lost
1#710:55 AMStarboard+66.59 m0.7 m
2#510:51 AMStarboard+59.51 m0.1 m
3#2011:42 AMStarboard+59.18 m0.4 m
4#911:05 AMStarboard+55.47 m1.2 m
5#810:58 AMPort+52.91 m7.5 m
6#610:53 AMPort+51.96 m0.0 m
7#2111:45 AMPort+49.82 m5.8 m
8#1811:36 AMStarboard+47.43 m6.2 m
9#1711:35 AMPort+45.42 m6.6 m
10#2211:47 AMStarboard+45.28 m0.6 m

Speed through each tack

Pick the tacks you want to compare — click to add one, click again to drop it. 0s is the tack itself. Each line takes the colour of its own chip; the "#" is the same tack number as the table above. Speeds are smoothed with a 4-second average so the shape of each turn reads through the GPS noise; the figures in the table are from the raw track.

Compare:
0123456kts-20s-10s0s+10s+20s#7 — SOG (rank 1 by distance made good)
#7SOGsmoothed over 4s

Gybe classification

A turn counts as a gybe when it's downwind of head-to-wind and clears this heading-change minimum (tacks always need >45°). Lower it if real gybes are missed, raise it if wobble gets misclassified. Affects every gybe analysis below.

Gybe comparison (±30s)

Manoeuvre instantDarker = further made good

Same as the tack comparison, but for gybes, ranked by distance made good downwind. Has its own before/after window.

-50m0m50m-100m-50m0m50m100mtoward wind ↑#14 · new tack Port — made good +79.19 m (rank 1)#14 — made good +79.19 m (rank 1)1#13 · new tack Starboard — made good +74.61 m (rank 2)#13 — made good +74.61 m (rank 2)2#12 · new tack Port — made good +73.05 m (rank 3)#12 — made good +73.05 m (rank 3)3#27 · new tack Port — made good +68.50 m (rank 4)#27 — made good +68.50 m (rank 4)4#15 · new tack Starboard — made good +59.85 m (rank 5)#15 — made good +59.85 m (rank 5)5#28 · new tack Port — made good +39.49 m (rank 6)#28 — made good +39.49 m (rank 6)6The manoeuvre itself (t = 0)
Rank # Time New tack Made good Lost
1#1411:28 AMPort+79.19 m1.3 m
2#1311:27 AMStarboard+74.61 m0.4 m
3#1211:22 AMPort+73.05 m0.4 m
4#2712:11 PMPort+68.50 m0.0 m
5#1511:33 AMStarboard+59.85 m10.6 m
6#2812:21 PMPort+39.49 m0.0 m

Speed through each gybe

Pick the gybes you want to compare — click to add one, click again to drop it. 0s is the gybe itself. Each line takes the colour of its own chip; the "#" is the same gybe number as the table above. Speeds are smoothed with a 4-second average so the shape of each turn reads through the GPS noise; the figures in the table are from the raw track.

Compare:
01234567kts-20s-10s0s+10s+20s#14 — SOG (rank 1 by distance made good)
#14SOGsmoothed over 4s

Top mark rounding comparison (±30s)

Manoeuvre instantDarker = further made good

Every top-mark rounding, overlaid and ranked by distance made good downwind afterward — helps spot a slow or wide rounding. Has its own (typically wider) before/after window.

-50m0m50m0mtoward wind ↑#3 — made good +17.05 m (rank 1)#3 — made good +17.05 m (rank 1)1#1 — made good +12.65 m (rank 2)#1 — made good +12.65 m (rank 2)2The manoeuvre itself (t = 0)
Rank # Time Made good Lost
1#312:00 PM+17.05 m34.3 m
2#111:16 AM+12.65 m13.6 m

Speed through each top-mark rounding

Pick the roundings you want to compare — click to add one, click again to drop it. 0s is the rounding itself. Each line takes the colour of its own chip; the "#" is the same number as the table above. Speeds are smoothed with a 4-second average so the shape of each rounding reads through the GPS noise; the figures in the table are from the raw track.

Compare:
012345kts-20s-10s0s+10s+20s+30s#3 — SOG (rank 1 by distance made good)
#3SOGsmoothed over 4s

Bottom mark rounding comparison (±30s)

Manoeuvre instantDarker = further made good

Every bottom-mark rounding, overlaid and ranked by distance made good upwind afterward. Has its own before/after window.

-40m-20m0m20m0m20m40m60mtoward wind ↑#2 — made good +43.92 m (rank 1)#2 — made good +43.92 m (rank 1)1#4 — made good -2.79 m (rank 2)#4 — made good -2.79 m (rank 2)2The manoeuvre itself (t = 0)
Rank # Time Made good Lost
1#211:34 AM+43.92 m8.3 m
2#412:25 PM-2.79 m—

Speed through each bottom-mark rounding

Pick the roundings you want to compare — click to add one, click again to drop it. 0s is the rounding itself. Each line takes the colour of its own chip; the "#" is the same number as the table above. Speeds are smoothed with a 4-second average so the shape of each rounding reads through the GPS noise; the figures in the table are from the raw track.

Compare:
01234567kts-30s-20s-10s0s+10s+20s+30s#2 — SOG (rank 1 by distance made good)
#2SOGsmoothed over 4s

Tacks & gybes

# Time Type New tack Heading Speed (SOG, before → min) Recovery

Sail Smarter Race Analytics is an independent project. Not affiliated with, endorsed by, or connected to Vakaros or Velocitek — those names, and the VKX and VTK file formats, are referred to only to describe compatibility. All trade marks are the property of their respective owners.