Hawaiian Islands

Hawaiian tides are some of the smallest you will plan around anywhere — mean range at Honolulu Harbor is about half a metre, and the daily pattern leans diurnal more than semidiurnal. Most days produce one clear high and one clear low, with a smaller secondary cycle that often barely registers above the noise. The islands sit in deep central Pacific water far from any continental shelf, so the astronomical forcing has nothing to amplify against. Snorkellers at Hanauma Bay and reef walkers at Waikīkī read the table mostly for the lowest lows around new and full moons, when limu beds and inner-reef shelves come out of the water that otherwise stay covered all month. North-shore swell and a steady trade-wind setup against the southern shore can each shift water level a few centimetres on top of the predicted signal — small numbers in absolute terms, but proportionally large given the tiny range. Tsunami events override everything, and the Pacific Tsunami Warning Center is the authoritative real-time source.