Puerto Rico

Puerto Rico occupies a transitional position between the Atlantic Ocean and the Caribbean Sea, and its tidal character reflects that geography. The north coast at San Juan faces the open Atlantic; the south coast at Ponce faces the Caribbean. Spring tidal range on the north coast runs 0.4–0.6 m, mixed semidiurnal; on the south coast the range is slightly smaller, 0.3–0.4 m, with more pronounced diurnal inequality — the two daily highs can differ by 0.1–0.2 m and the pattern shifts toward one dominant cycle per day through parts of the lunar month. NOAA operates primary harmonic tide stations at San Juan (Station 9755371) and Maguyes Island near Ponce (Station 9759110), making Puerto Rico one of the better-covered territories in the US Caribbean tide network. Hurricane season June through November is the dominant coastal hazard; storm surge from a major hurricane makes the 0.4 m astronomical range irrelevant — Hurricane Maria's surge reached 1–2 m above normal in several south-coast communities in 2017. Rincón on the west coast is the island's surf capital, hosting the 1968 World Surfing Championships and drawing consistent North Atlantic swell November through February. The Mona Passage between Puerto Rico and the Dominican Republic is humpback whale calving ground from January through March.