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.
Resolve the exact named coastal and offshore forecast sectors before crossing a national boundary. Island lee, headland acceleration and a narrow channel can differ from a broad Mediterranean model cell.
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
Compare Greek forecasts with Turkish coastal products near the boundary.
Dodecanese legs may cross Greek island channels and then approach the Turkish coast. Mark where the forecast responsibility changes.
Check HNMS and MGM for the relevant sides of the leg; compare gusts and short steep seas in a channel with conditions at the berth.
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.
Local passage-planning dossier
Separate Greek island waters, Turkish coastal products and the final exposed approach.
Forecast sectors and coverage
Look up Southeast Aegean Ikario, Samos Sea and Rodos Sea in the current HNMS product where relevant. These are candidate sectors to verify, not a statement that every Dodecanese route crosses all three. Add MGM if the chosen leg approaches Turkey.
Weather-sensitive legs
Plot the island gaps and check both sides of a channel. Harbour shelter, an offshore model cell and the narrowest section may describe different conditions. A short crossing still requires a separate arrival-side assessment.
Observations, sea state and reassessment
Compare Greek and Turkish products at matching valid hours and units; disagreement is a reason to inspect issue times and coverage, not a vote. A coastal station does not establish the offshore wave height.
Worked planning scenario — not a live forecast
Before a cross-border island leg, record one source and reassessment time for each side. If the return is upwind or an arrival forecast worsens, assess a shorter plan without assuming that the outward window also permits the return.
Official products by task
- HNMS marine bulletin — Locate the named Greek sea sectors; check the actual issue, not a city forecast.
- HNMS sea-area warnings — Marine warning entry point; distinguish sea warnings from land alerts.
- MGM 24-hour marine forecast — Turkish coastal sea products; choose Aegean or Mediterranean section as applicable.
- HCMR POSEIDON monitoring tools — Find observing platforms and distinguish measurements from model fields; check gaps and timestamps.
Sector names help you locate the issuing product; they are not an automatic route-coverage match. Open the current issue and check boundaries, issue time and validity. This page does not display current warnings; an unavailable product does not mean no hazard.
Countries & territories
- Greece
Ionian coast, Saronic Gulf and open Aegean island passages require different plans.
- Turkey
Choose the Aegean or Mediterranean coastal plan and evaluate the bay exit separately.
Build your passage brief
Bring your route, leg timings, vessel and crew profile, checked sources and reassessment triggers into the brief. Personal AI analysis and expert review are available to invited closed-test participants; a port page does not extend the calculation service’s coverage.
A Sailing Weather editorial guide to local conditions, practical passage preparation and marine-weather sources. Source and structure review: 27 September 2026. For a specific passage, check current issues, validity and forecast coverage. The skipper retains the final decision and responsibility.
Build a bilingual source chain
A Kos–Kalymnos–Rhodes itinerary does not stay inside one named weather sector, and a Turkish diversion changes the source requirements again. Keep the original Greek or Turkish sector name beside its translation in the brief. Compare bulletins at the same valid hour; differences may reflect area boundaries, issue times or units, not merely competing forecasts. Consult both services before a cross-border leg, without implying that a national coast defines a weather-zone boundary.
- HNMS marine sectors — Named Greek sea sectors; not automatic route matching Direct product verification is limited; obtain the current issue from the issuer.
- MGM Turkish-coast marine forecast — Turkish marine products; images require reading their stated coverage
Separate a strait from the following arrival
Put narrow-channel transit and the open approach to the next island in different rows. An observation near Kos town cannot validate the later Rhodes approach. For each row ask which coast is exposed after the forecast shift, and whether swell can enter the intended stopping place even if the local wind falls. The boat's motoring capability and the crew's endurance belong in this comparison, not in a universal regional limit.
- HNMS marine sectors
- HCMR POSEIDON observing components — Greek marine observing infrastructure; operating status must be checked Direct product verification is limited; obtain the current issue from the issuer.
Keep a cross-border alternative operational
A weather alternative involving another country also needs independently verified entry, harbour and communications information. Do not label it a refuge simply because its map looks sheltered. Recheck the return passage and the next day's sector coverage before extending a charter itinerary. If current Greek or Turkish products cannot be retrieved, state which leg lacks evidence instead of smoothing that gap into a reassuring summary.
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.