Long Hai, Southeast Vietnam tide times

Long Hai sits in a semicircular bay in Bà Rịa-Vũng Tàu province, 30 km south of Bà Rịa city. Rocky headlands close each end of the bay. The town is small enough that the tidal rhythm is still visibly embedded in daily life — the fishing fleet, the beach width, and access to the Dinh Cô temple all move with the water.

The tidal range at Long Hai is among the larger along the South China Sea's southern Vietnamese coast. Mean spring range is 2.0–3.0 m — substantially bigger than at Mui Ne or Hoi An. The regime is diurnal-dominated mixed: one primary high and one primary low per day are the governing cycle, with any secondary event small enough that most users treat the day as a single tidal swing. The low tide typically falls in the early morning and the high in the early afternoon during the drier months; this inverts partially with the season, so checking the specific day's table matters more here than at lower-range sites.

The single most striking tidal feature at Long Hai is the Dinh Cô temple. The Dinh Cô Lady shrine occupies a granite outcrop at the southern end of the bay. At high spring water the rock is entirely surrounded by sea — a small island. As the tide falls through the ebb, a sand and rock causeway emerges connecting the shrine to the main beach. At the lowest spring tides of the month, the causeway is fully exposed and dry: roughly 60 m of packed sand and flat rock, 2–4 m wide, walkable in sandals. The window for dry-foot access is approximately two hours either side of the lowest daily low, which at Long Hai can be as low as 0.2–0.4 m above chart datum during spring cycles. Pilgrims visit the temple year-round, and on the spring low tides they walk the causeway in significant numbers — it is a meaningful local ritual, not just a tourist attraction. The causeway is never marked with permanent signage; it simply appears and disappears with the tide. At a neap low water of 0.8–1.0 m, the causeway is wet and passable with care but not dry. At high water it is submerged under 1.5–2.0 m of sea.

For photographers, the composition possibilities at the Dinh Cô outcrop change with each tidal state. At high tide the granite dome sits in open water against the headland backdrop — shoot from the beach with a long lens for a clean island shot. As the causeway emerges, a mid-tide frame captures the strip of sand with the temple at its end and people crossing. At low tide, shoot from the causeway itself looking back at the bay with the fishing boats and southern headland behind you.

The beach itself responds dramatically to the 2.0–3.0 m range. At high tide the beach width above the waterline narrows to 15–20 m in front of the central town area. At low spring water the beach widens by 80–100 m and the headland rocks at both ends of the bay expose fully, connecting the main beach to smaller coves around each headland. The northern headland rock connection, accessible only in the two hours around low water, leads to a narrow cove with calmer water and no fishing boat traffic — good for a swim without distraction. The southern headland connection leads around toward the Dinh Cô approach.

The fishing boats using Long Hai as a base are motorised inshore vessels, mostly 6–10 m fibreglass and wood hulls, working within 20 km of shore for squid and bottom fish. They work the bay sides for departure and return timing, with launches on the flood tide in the afternoon and returns in the early morning on the ebb. The sheltered bay geometry means sea state inside the bay is manageable at most tide states for the local fleet size.

Hồ Cốc Beach, 30 km northeast along the coast through Bà Rịa-Vũng Tàu province, is the major undeveloped beach of the region — 17 km of open sand accessible through rubber plantations. It sits on an exposed coast without the headland protection of Long Hai, so its wave energy and beach character differ. On clear days from the Long Hai southern headland, the cape at Vũng Tàu (historically Cap Saint-Jacques) is visible to the west, 40 km by sea, its lighthouse and communication towers identifiable on the horizon. Vũng Tàu is the largest city in the province and its tidal range is similar to Long Hai — both sit in the same regional tidal regime.

Tide data for Long Hai, Southeast Vietnam comes from the Open-Meteo Marine API, a gridded model product. Timing accuracy is ±45 minutes, height accuracy ±0.3 m — usable for trip planning, not for navigation.