Kōchi tide times

Predictions: Open-Meteo Marine (MeteoFrance SMOC, 0.08° grid) — heights relative to MSL (not chart datum / LAT). Model-derived.

Model-derived from a global ocean grid. Useful indication; expect about ±45 minutes on average vs. a local harmonic gauge, individual stations vary widely. See /methodology for per-region detail. Not for navigation.

Conditions as of 08:00 local time. Refreshes daily.

Predictions: Open-Meteo Marine (MeteoFrance SMOC, 0.08° grid) — heights relative to MSL (not chart datum / LAT). Model-derived. · Not for navigation.

The angler tradition for major/minor fishing windows: major ≈3-hour windows around moon transit and opposition; minor ≈2-hour windows around moonrise and moonset. Times are Asia/Tokyo local. Folk tradition, not a scientific forecast.

Next spring tide on Sun 17 May (range 2.0m). Next neap on Thu 14 May.

Spring tides cluster around new and full moons (biggest swings). Neap tides land on quarter moons (smallest swings). See the spring tide and neap tide glossary entries for the why.

Kōchi is the capital of Kōchi Prefecture on Shikoku's Pacific coast, built on a flat river delta at the head of Tosa Bay — a wide, deep embayment opening south into the Pacific. The city is separated from the Seto Inland Sea side of Shikoku by the Shikoku Mountains. The Pacific orientation defines everything here: direct swell exposure, high typhoon frequency, and an open-ocean tidal regime. The tidal regime at Kōchi is semidiurnal with a spring range of approximately 2.0 m above Chart Datum. Mean high water springs is around 1.5 m; mean low water springs around 0.5 m. Neap range narrows to 0.8–1.0 m. Tosa Bay swell climate is one of the most exposed in Japan: southerly Pacific swell reaches the bay with minimal attenuation and can run to 4–5 m at the outer headlands in typhoon conditions. For the offshore fishery, Kōchi is Japan's most important tuna and bonito port. The skip-jack tuna (katsuo) one-pole fishery operated from Kōchi has been the economic base of the coastal culture here for centuries. Katsuo no tataki — flame-grilled bonito with garlic and ginger — is Kōchi's signature dish. The offshore fishing grounds in the Kuroshio Current south of Tosa Bay are among the richest in Japan; tidal state is secondary to the Kuroshio's meanders and the seasonal katsuo migration for offshore boats. For inshore anglers, Tosa Bay's 2.0 m spring range creates productive tidal flat conditions at river mouths. The Kokubu River mouth at the eastern edge of the city is a traditional mullet and sea bass (suzuki) fishery; bass enter the estuary on the flooding tide and are fished from the river-mouth bank. The flooding window — 1–2 hours before to 1 hour after high water — is the productive period. Surfers use the outer beaches east and west of the city — Katsurahama (6 km south) and beaches near Aki and Tosa City — for Pacific swell. Swell of 1.0–2.0 m is common October through March; typhoon swells reach 4–6 m at the outer point breaks. Tidal state matters at the rocky reef breaks: on a 2.0 m spring range, the difference between high and low water at a shallow reef break is the difference between rideable wave and closed-out shore pound. Most reef breaks work best on the middle portion of the tide — the upper half of the ebb. Katsurahama Beach, 6 km south, is the most photographed beach in Kōchi Prefecture: a curved cove below the cliffs with a bronze statue of samurai hero Sakamoto Ryōma at the clifftop. The beach is not safe for swimming due to Pacific shore-break and rip currents, but the 2.0 m tidal range provides photographers with a broad sandy foreground at low water and a wave-at-the-rocks composition at high water. Typhoon season runs July through October. Direct hits on Kōchi are more frequent than on most of Japan's Pacific coastline. A direct-hit storm surge of 2–4 m arriving at spring high water (1.5 m above Chart Datum) creates total water levels of 3.5–5.5 m above Chart Datum in the low-lying delta areas of the city. All tide predictions for Kōchi come from the Open-Meteo Marine gridded model. Timing accuracy is ±45 minutes; height accuracy is ±0.3 m above Chart Datum.