Saint John, New Brunswick tide times

The hero block shows the next high tide at the Saint John harbour gauge in local Atlantic time (AST in winter, ADT in summer). The 7-day table covers all the highs and lows. High water at Burntcoat Head across the bay on the Nova Scotia side lags Saint John by about three hours, because the propagating tide takes that long to reach the head of the basin.

The Bay of Fundy resonates close to the natural period of the lunar semidiurnal forcing, so each tide reinforces the previous one as it propagates up the funnel-shaped basin. The further into the bay you go, the bigger the swing. Saint John sits closer to the mouth than to the head and runs about 6.9 metres mean range, with springs past 8.5 metres. The world record at Burntcoat Head deeper into the basin is 16.3 metres.

Open-Meteo Marine, a gridded global ocean model. Useful for daily planning around Saint John harbour, the Reversing Falls, and the Fundy Trail Parkway. For authoritative Canadian Maritime tide data, the Canadian Hydrographic Service publishes the official tide tables and operates the Saint John reference gauge — given the working currents in the Bay of Fundy, the CHS tables are the only product to use for any navigational purpose.

The slack windows at the Reversing Falls run for about twenty minutes either side of high and low water, four times a day. At high water the tide is at maximum and the river is held back at the same level — the water surface is calm and navigable. As the tide drops, the river runs out and produces standing waves and a downstream cataract; at low water the slack returns. As the tide rises, the bay overpowers the river and pushes water upstream, producing the upstream cataract — the reversed falls. The four daily slacks are the only safe transit windows.

No. For piloting in or out of Saint John harbour, transiting the Reversing Falls, or working the Bay of Fundy waters use the Canadian Hydrographic Service authoritative tide tables, the Atlantic Pilotage Authority guidance, and the Canadian Coast Guard notices to mariners. Bay of Fundy currents are working-hazardous and can run over five knots on the change of tide; the Reversing Falls itself is impassable except at the four daily slack windows.