This is a pre-passage source and decision desk, not a current forecast or clearance to depart. The map is centred approximately on the area, not on your route or a forecast-zone boundary.
Coastal, reef, island and offshore products are not interchangeable. Compare the official warning with swell direction, local tide and exposed arrival before relying on any model-based route.
1. Primary sources
Open current bulletins and warnings for every sea area on the route. These links are starting points, not a promise that each covers the whole location; if unsure, identify the issuer through WMO–IMO.
2. Route and local effects
Use the correct island coastal zone plus Pacific offshore warnings for longer legs.
Hawaiian island crossings can encounter channel acceleration and swell unlike conditions inside a leeward harbour.
Use the NWS Hawaii marine zone for each channel, plus warnings and swell information. Note where a change of conditions would leave a feasible alternate arrival.
How to use this source set
Start with the warning, then the marine text for the exact named area. If the route crosses a zone boundary, obtain both bulletins. Note issue and valid times, wind units and the meaning of wave height. Where a link opens an agency portal, navigate to its current marine product; a homepage is not itself a forecast.
Compare with an exposed station or buoy if available. Check its position and observation time: a sheltered station does not overturn a warning for an open channel. If a bulletin is missing or stale, identify the issuing service via WMO–IMO and defer the decision until current information is available.
Before-passage check
- Mark departure, exposed legs, arrival and feasible diversions; find the responsible named marine areas for each.
- Check warnings, issue and valid times; assess conditions when you expect to reach each leg, not only at departure.
- Compare wind and gusts, waves and swell, visibility, thunderstorms and local effects; do not infer a strait from a sheltered harbour.
- Compare recent observations where available, noting their time and exposure; a mismatch calls for another check.
- Set the next bulletin check, a reassessment trigger, an alternative and a backup communication channel.
Model map — optional
Windy is a third-party model display, not the issuer of official warnings. Choose a layer and check its valid hour and model run. Nothing loads until you click.
Without JavaScript, open the map separately.
If connectivity fails
Before departure, save the current official text bulletin and warning with issue time. Arrange another way to receive updates, such as an appropriate coastal broadcast, NAVTEX or satellite channel. A saved map cannot replace new warnings.
How to choose weather tools · All sailing areas
Scope: Source list assembled 25 September 2026; check its freshness and coverage before use. This public area guide is not a current personalised forecast, navigational notice service or safety verdict. Personalised forecasts with AI and experts are in closed testing; public booking is not open. The skipper makes the decision.
Choose the channel product, not the harbour's calm reading
NWS Honolulu's marine desk links Hawaiian coastal/channel products, offshore guidance, warnings and observations. For an inter-island passage, select the actual channel and both approach areas; a Honolulu city or harbour forecast does not describe the full crossing. Keep the applicable warning visible when comparing model departure windows. The ocean swell assessment and the receiving harbour's access remain distinct evidence requirements.
- NWS Honolulu marine products — Hawaiian coastal/channel, offshore, observations and swell information.
Swell source and arrival side matter alongside channel wind
Compare wind waves with incoming swell direction and period at the exposed passage and intended landfall. A leeward start can feel comfortable while the open channel or another side of the receiving island is different. Use observations only for their actual site and variables, and distinguish coastal sea-state products from beach surf information. A forecast for a beach is not a verified vessel route or entrance clearance.
Reassess the receiving island under delayed progress
Test an inter-island arrival with slower progress and the next warning update. If arrival direction, visibility, light or local harbour information changes, revisit the destination before the exposed commitment rather than simply picking the model with smaller wind. A different island or harbour adds its own crossing and approach evidence. For a longer ocean continuation obtain the applicable offshore/high-seas product instead of extending the channel forecast.
- NWS Honolulu marine products
- NWS marine zone directory — Coastal, offshore and high-seas product selection; not automatic route matching.
Editorial review of this material: 27 September 2026. This date concerns the page content; check current forecast issue times and validity at the original sources.
- United States
Choose a bay, coastal, offshore, Great Lakes or ocean product for the actual track.