Deployment day: we said 0.12, she said 0.117
After a week of surgery (a resoldered thermometer, a recalibrated gyroscope, a fixed radio bug that had made her deaf to instructions), the buoy went back on her mooring off Marbella. What happened next was the best hour of the project so far.
The night before
She spent the night on the bench in power-saving mode: wake every three hours, check in, sleep. Schedules like that drift, because every wake costs a few minutes of radio time and "every three hours" slowly slides later. Our trick: the server recalculates her sleep at every single check-in and clamps the last one to the seven o'clock edge. The drift can move the middle of the night but never the end of it. She woke at 07:03. Boat left at nine.
The measurement
By late morning she was clipped on and settled. First still reading: basically zero. Then at 11:15, the first honest number of the new season: 0.117 m at 6.2 seconds, with all three of her internal estimators agreeing to the millimetre. That agreement is the signature of a clean measurement.
And here's the part you can't buy. We were still floating next to her. Someone asked, "go on then, how big are these waves?" The crew's answer: "it's basically glass... maybe 0.12?"
Instrument: 0.117. Humans: 0.12. Half a centimetre apart. A wave buoy is validated the day the people in the water and the electronics in the water stop disagreeing.
The honesty ledger
Two readings from the boat ride showed 13 to 16 cm of "waves" that were really just handling. A buoy in a moving boat measures the boat. We corrected both, and this is the house rule worth stating: every corrected number stays marked as corrected, forever, with the original kept right next to it. The app should never show you nonsense, and we should never be able to pretend the nonsense didn't happen.
One more dial got turned that day. The sea felt like glass at 0.117 m because those waves were 60 metres long, a slope of 0.2%, invisible. The same height packed into 2-second waves is ten times steeper and clearly textured. So the scoring now understands steepness, and a long lazy swell reads as calm as it feels. The crew taught the formula something that morning.