Coos Bay (Charleston)
A commercial bar on the southern Oregon coast. Big long-period swell from the west stacks up on the ebb; the Coast Guard restricts it in hazardous conditions.
A sizeable, long-period swell is running, which stands up over the bar.
Updated 9:54 PM PDT. Tide from Charleston (1 mi). Swell from the nearest buoy (48 mi). Wind from the National Weather Service. Conditions change fast and this data can be hours old.
The US Coast Guard and NWS report and, when needed, restrict this bar. Check it, and follow it, before you cross.
Tide windows ahead
High-water slack is the classic favorable window: weakest current and the most water over the bar. Times are local to the tide station.
How to time an inlet crossing
Three things decide how an inlet behaves: the current, the wind, and the swell. The current is worst on a strong ebb, when a lot of water is pouring out over a shoaling bar. The wind matters most when it blows against that ebb: opposing flow shortens and steepens the waves. And a long-period swell from seaward stands up as it feels the bottom, turning a gentle offshore sea into breakers in the entrance.
So the easier crossings are near high-water slack or on the flood, with the wind off the nose of the ebb and the swell down. Cross in daylight when you can, watch the entrance before you commit, and remember that a bar can look calm from seaward and be breaking on the inside. None of that replaces the Coast Guard bar report where one exists.
Frequently asked
When is the best time to cross Coos Bay (Charleston)?+
Generally near slack water at high tide, or on the flood, with the wind and swell down. The current is weakest around the high and low, and the most water is over the bar near high tide. The time to be wary is a strong ebb, especially against an onshore wind or swell.
Why is wind against tide so dangerous at an inlet?+
When the wind blows against the outflowing ebb, it shortens and steepens the waves. Add a shoaling bar and a long-period swell and a modest offshore sea can become steep, closely spaced breakers right in the entrance. That opposing-flow set-up is the single biggest reason inlets turn dangerous.
Is this tool telling me it is safe to cross?+
No. It shows relative conditions to help you plan, never a go or no-go decision. Bars and inlets shift, our data can be hours old and from a buoy miles away, and only you can judge your boat and crew. Where a US Coast Guard bar report exists, that is the authority. If in doubt, don't go out.
Planning aid only, not for navigation and not a safety clearance. Favorability is a relative guide from tide timing, the current wind, and swell that may be hours old and measured miles away. Bars and inlets shift, and only you can judge your boat and crew. Where a US Coast Guard bar report exists it is the authority. If in doubt, don’t go out.
