Skip to content

Research dataset

Coastal sailing performance

Separate sailing records from Valencia, San Francisco, Auckland, and the Solent. Select a location to compare its maneuvers and wind conditions. The records cover different boats.

Valencia · 2005-06-13 · 13 analyzed tacks · 1 unavailable

Instrument performance

Speed through the turn

13 analyzed tacks1 censored / not analyzed5.2 s median turn duration16.2 s median recovery

Aligned tack speed

13 turns · BSP kt · median / IQR
5.46.98.49.9-2920.369.7119BSP · kttime · s
Each turn contributes at most one boat speed (BSP) value per second. Gaps of up to 3 seconds are interpolated. Faint lines show individual turns.

Selected tack

5.77.18.59.9-300306090120BSP · kttime · s
Entry 7.1 · low 5.9

Wind angle through turn

TWA °
-147.6-84.9-22.140.6-300306090120TWA · ° unwrappedtime · s
Recorded true wind angle (TWA), unwrapped across ±180° to keep the trace continuous. The cursor shows the original signed angle. The dashed line marks the detected turn at 0 seconds.

Turn duration

13 tacks · s
047counts3.512.521.6
Hover or focus a bar to inspect its interval and count.
Observed distribution; median 5.2 s.

Recovery

13 tacks · s
023counts11.71620.3
Hover or focus a bar to inspect its interval and count.
Observed distribution; median 16.2 s.

Acceleration

13 tacks · s
024counts611.216.4
Hover or focus a bar to inspect its interval and count.
Observed distribution; median 11.2 s.

Entry speed versus recovery

13 analyzed tacks · BSP kt / recovery s
11.714.617.420.37.17.78.38.8recovery · sentry BSP · ktTurn: 7.1 kt, 13.1 sTurn: 7.3 kt, 19.1 sTurn: 7.8 kt, 16.2 sTurn: 8.2 kt, 12.1 sTurn: 8.5 kt, 15.5 sTurn: 8.8 kt, 17.5 sTurn: 8.8 kt, 17.6 sTurn: 7.4 kt, 14.6 sTurn: 8.6 kt, 17.3 sTurn: 8.3 kt, 11.7 sTurn: 8.6 kt, 18.6 sTurn: 8.7 kt, 20.3 sTurn: 8 kt, 12.3 s
Hover or focus a point to inspect entry speed and recovery.
Each point represents an analyzed tack. Recovery is the time taken to return to the speed threshold based on entry speed.

Distance lost through the turn

RankSession / turnEntry / low BSPTurn / accelerationLossRecoveryStatus / reason
1Valencia · 2005-06-13 · 6/13/20058.7 kt / 6.6 kt5.2 s / 16.4 s17.7 m20.3 sAnalyzed
2Valencia · 2005-06-13 · 6/13/20058.6 kt / 6 kt13.8 s / 13.8 s15.4 m18.6 sAnalyzed
3Valencia · 2005-06-13 · 6/13/20058.8 kt / 6.5 kt19.9 s / 12.1 s14.1 m17.5 sAnalyzed
4Valencia · 2005-06-13 · 6/13/20058.8 kt / 6.8 kt18.1 s / 12.1 s13.7 m17.6 sAnalyzed
5Valencia · 2005-06-13 · 6/13/20058.6 kt / 6.4 kt3.5 s / 12.1 s13.3 m17.3 sAnalyzed
6Valencia · 2005-06-13 · 6/13/20057.3 kt / 5.4 kt21.6 s / 13.8 s11.9 m19.1 sAnalyzed
7Valencia · 2005-06-13 · 6/13/20057.4 kt / 5.9 kt5.2 s / 8.6 s6.6 m14.6 sAnalyzed
8Valencia · 2005-06-13 · 6/13/20058.3 kt / 6.2 kt6 s / 6.9 s6.5 m11.7 sAnalyzed
9Valencia · 2005-06-13 · 6/13/20058.2 kt / 6.5 kt19.9 s / 6 s5.7 m12.1 sAnalyzed
10Valencia · 2005-06-13 · 6/13/20057.1 kt / 5.9 kt5.2 s / 6 s-0.3 m13.1 sAnalyzed
11Valencia · 2005-06-13 · 6/13/20058 kt / 6.4 kt5.2 s / 8.6 s-0.5 m12.3 sAnalyzed
—Valencia · 2005-06-13 · 6/13/20057.8 kt / 6.3 kt5.2 s / 8.6 s—16.2 sAnalyzed
—Valencia · 2005-06-13 · 6/13/20054.9 kt / 2.5 kt— / ———Not analyzed: no held pre-turn TWA-stable departure observed; TWA settlement censored or missing within observation limit; BSP recovery to threshold censored or missing before observation boundary
Entry hold compares recorded distance with the distance traveled at a constant entry speed. Each metric uses its available measurements. Missing values include the reason they could not be calculated.

Session comparisons

1. Valencia · 2005-06-13

BSP entry

kt · median / IQR
4.45.66.98.19.3kt114/14 · c1
Hover or focus a session to inspect its median, IQR, and coverage.
n shows available measurements / events; c counts censored events.

TWA turn duration

s · median / IQR
1.36.912.518.223.8s113/14 · c1
Hover or focus a session to inspect its median, IQR, and coverage.
n shows available measurements / events; c counts censored events.

Speed recovery

s · median / IQR
10.713.31618.721.4s113/14 · c1
Hover or focus a session to inspect its median, IQR, and coverage.
n shows available measurements / events; c counts censored events.

Loss

m · median / IQR
-2.638.614.219.8m111/14 · c1
Hover or focus a session to inspect its median, IQR, and coverage.
n shows available measurements / events; c counts censored events.

Wind conditions differ between sessions.

Empirical speed polar

Angle: absolute TWA · radius: BSP in knots
True wind speed

No measured speed bins are available.

Coverage

cells show sample counts
TWS \ TWA0–30°30–40°40–50°50–60°60–75°75–90°90–105°105–120°120–140°140–160°160–180°
0–6 kt19539114645484584012
6–9 kt31764445026430235236631260754538
9–12 kt87883368474367622612255655
12–15 kt701675387404166348215185453
15–18 kt182183823733213234—
18–24 kt———————————
24–40 kt———————————

Blank cells have no observations. They do not indicate zero boat speed.

BSP across true wind

11977 samples · kt
TWS ↓
TWA →0–30°30–40°40–50°50–60°60–75°75–90°90–105°105–120°120–140°140–160°160–180°0–6 kt
2.8
3.8
4.7
4.3
4.3
4.6
4.3
4.1
3.8
5.7
4
6–9 kt
3.8
7.6
7.6
6.1
4.8
5.2
5.2
4.9
6.9
6.7
5.9
9–12 kt
7.5
8.2
8.1
7.3
5.4
6.8
8
8.4
8.1
9.6
8.1
12–15 kt
8.2
8.4
8.4
8.4
8.5
10.6
11.2
10.9
10.6
10.6
9
15–18 kt
8.5
8.4
8.2
8.1
7.9
9.4
11.8
11.5
11.6
11.7
–
Touch, hover, or focus a wind cell for BSP and sample count.
Rows group true wind speed (TWS); columns group absolute true wind angle (TWA). Cells show median boat speed in knots. Blank cells have no accepted observations.

Upwind tack balance

Port minus starboard · knots
TWS · kt|TWA| · °Samples
Port / stbd		Δ BSP · kt
6–930–40100 / 544-1.2
6–940–5069 / 381-0.2
6–950–60121 / 143+1.3
9–1230–40566 / 317+0.1
9–1240–50284 / 84+0.1
12–1530–40761 / 914-0.1
12–1540–50231 / 156+0.4
15–1830–4047 / 171+0
Positive values indicate faster sailing on port; negative values indicate faster sailing on starboard. Each wind bin has at least 30 samples per tack. These differences alone cannot establish a calibration error.