For each boat: how far behind you they can finish and still tie you on corrected time - any closer and they beat you (+ you give them time), or how far ahead of you they must finish (− they give you time). Columns are your elapsed race time.
Race log - estimate vs actual
Marks are the official SI Appendix A positions (2024 book - check course numbers against the 2026 course board each morning). Island legs are centre-to-centre, so real sailed distance is slightly longer. Polars are rough ORC-style estimates scaled from each boat's actual design, paced by its IRC TCC.
AIS setup (aisstream.io)
Free key at aisstream.io. Add each boat's MMSI below to auto-track distance. Your own position comes from this phone's GPS. Without AIS, just type distances in manually. On a phone, rotate to landscape to edit MMSIs.
Distance + ahead/astern gives a time gap at fleet speed. Combined with the handicap owed at the current elapsed time: if the race finished now, this is where you'd sit on corrected time. + owed: they can finish that far behind you; − owed: they must be that far ahead.