Ritidian Point 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 09:00 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 Pacific/Guam local. Folk tradition, not a scientific forecast.

Next spring tide on Mon 18 May (range 1.0m). 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.

Ritidian Point is the northernmost tip of Guam — a US Fish & Wildlife Service refuge covering 250 hectares of limestone forest, white sand beach, and offshore reef. The point faces north and northeast into the open Pacific; there are no resort hotels, no jet ski rentals, and no restaurants. What Ritidian has is one of Guam's least-disturbed coral reef systems, a documented nesting beach for the critically endangered hawksbill turtle, a population of the Guam kingfisher (believed extinct in the wild, captive birds are slowly being reintroduced), and a set of ancient latte stone sites in the forest behind the beach. The tidal conditions at Ritidian follow Guam's mixed semidiurnal signal with a spring range of 0.5–0.7 m. The exposure here is different from the protected western bays: Ritidian faces north-northeast into the prevailing NE trade-wind swell. Even on moderate trade days the beach sees 0.5–0.8 m of shore break, and at spring lower-low water the extensive reef flat north of the point — extending 200–300 m from shore before the reef edge — is exposed to 0.1–0.3 m depth. This is prime territory for shore anglers willing to wade the flat to the reef crest. The reef flat at Ritidian is ecologically significant. It is one of the most intact reef-flat systems on Guam's northern coast, protected from fishing pressure and anchor damage by the Wildlife Refuge status. The coral coverage and fish density on this flat exceed anything accessible from Tumon Bay. Snorkellers and free-divers who visit at high water — when the flat is covered to 0.8–1.2 m and the outer reef slope drops to 5–15 m — encounter reef fish populations noticeably denser than at resort-adjacent sites. For anglers, Ritidian's reef flat at spring lower-low is the opportunity. The 45–60 minute window when the flat is at its shallowest allows anglers to wade to the outer reef crest and fish the surge zone with lures or live bait. Giant trevally of 5–15 kg cruise the outer edge of this flat on the flood; bonefish work the sandy pockets between coral heads on the flat surface during the low-water window. This is specialist fishing — the access requires correct timing, wading ability, and respect for the refuge regulations (check current USFWS permit requirements before fishing; some sections of the refuge may require permits). For photographers, Ritidian has two distinct visual environments. The beach itself — white sand, backed by limestone cliff and forest — gives a foreground for the dramatic reef and swell composition that the resort beaches further south cannot replicate. Dawn from the beach at Ritidian, when the sun rises directly behind the reef crest from the northeast, lights the breaking swell from behind with a backlit spray effect. This shot requires being on the beach at 05:50 in summer and 06:20 in winter. Low-water mornings extend the reef-flat foreground into the frame. The latte stone sites in the forest behind the beach are archaeological features — stone pillar foundations of pre-contact Chamorro structures, their mushroom-cap capstones (tasa) still in place at the best-preserved sites at Ritidian. These are not managed tourist sites with signs and paths; they are authentic in-situ features in secondary forest. A USFWS permit is required to visit the refuge; the Fish & Wildlife office in Mangilao manages access. Entry is from the main gate off Marine Corps Drive. For wildlife observers, the hawksbill turtle nesting season at Ritidian runs June through October, with individual nests scattered along the beach above the high-water line. Female turtles come ashore at night, typically on the high-water falling phase — the receding tide in the hours after high water provides sufficient depth for approach and a lower-energy exit. Observers must maintain 50 m distance from nesting turtles; flash photography is prohibited. Swimming at Ritidian is possible at high water in the cove section where the beach meets the reef at the east end. At lower-water states the entry over the reef flat requires wading 50–100 m before reaching swimmable depth. The NE trade-wind swell creates a shore break that is manageable at 0.3–0.5 m but becomes uncomfortable above 0.8 m. The USFWS refuge hours restrict access; the beach is closed at dusk regardless of tidal state. All tide predictions for Ritidian Point come from the Open-Meteo Marine gridded model. Timing accuracy is ±45 minutes; height accuracy is ±0.3 m above Chart Datum.