Can you actually predict dive visibility? You can predict the odds — honestly and usefully — if you stay local and keep score. Why global “exact number” apps overpromise, and how we built ours to be honest about uncertainty instead.

A month-in-review of California dive visibility for May 2026 - what the SpearFactor tool predicted, what the diver report network confirmed, where the predictions hit and missed, and the calibration lessons going into June.