From recorded runs, checked against an independent figure wherever one exists.
| Course | Ours | Published | Source |
|---|---|---|---|
| Boston Marathon | 821 ft | 815 ft | B.A.A., surveyed |
| Honolulu Marathon | 456 ft | 457 ft | FindMyMarathon |
| Rock 'n' Roll San Diego Marathon | 828 ft | 813 ft | FindMyMarathon |
San Diego checks the whole stat block — gain, descent, high point, net — all within about 2%.
The line. Averaged from recorded runs of the course, and verified by the ground it covers — never by its distance agreeing.
Elevation. USGS 3DEP, sampled every 10 meters along the measured line.
Climb. A rise counts once it clears 10 feet — the way a barometric altimeter counts, not a sum of every wobble.
The cross-check. Each seed run’s barometric recording, correlated against the model at the run’s own coordinates before a course publishes.
Bridges. A bare-earth model reads the water, not the deck. Decks are rebuilt only where the course crosses mapped water; ambiguous dips stay.
Refusals. When no instrument survives the cross-check, the page carries an attributed figure or nothing. Houston states FindMyMarathon’s 217 ft.
The chart. Every profile shares a floored vertical window, so a flat course looks flat.
Figures as measured August 2026; they move only when a course is re-measured. Each course page names the device that recorded it.