Distinguish North Sea/Wadden, inland lakes and Zeeland waterways before choosing data.
Choose a sailing scenario
Three water types need separate workflows: coastal/inlet exposure, lake wind/fetch and actual levels, and estuary/managed-waterway timing. Select the waterway first; KNMI sectors, RWS observations and lock notices answer different questions.
Season planning versus departure weather
Seasonal reputation helps shortlist a trip, but does not establish a departure window. Before fixing the passage, obtain current sea warnings, an issue valid across the planned legs and route-relevant observations. If the plan spans forecast horizons, schedule new checks rather than extending confidence beyond the data.
What the linked geography means
The links below include national waters, cross-border areas and, where relevant, overseas territories or onward passages. They are discovery links, not territorial boundaries or proof that one national bulletin covers every linked area. Follow each local desk to its own issuer.
Official products by task
- KNMI coastal waters — Named Dutch coastal, estuary and lake sectors; issue and validity are shown at the issuer.
- Rijkswaterstaat Waterinfo — Water levels and available water observations; check station, units and datum before comparison.
- Rijkswaterstaat IJsselmeer information — Lake water data, shipping notices and lock/bridge information; not an ocean tide table.
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.
Waters and sailing options
- Netherlands coast and Wadden Sea
Use named KNMI coastal sectors and a separate water-level/approach check.
- IJsselmeer and Markermeer
An inland-water sailing plan needs lake sectors, actual levels and lock information.
- Zeeland Delta
Separate sea-facing approaches, estuary sectors and managed inland waters.
- North Sea approaches
The North Sea needs national coastal products as well as the broader shipping-area forecast.
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.
Choose the water type from the crew's actual task
For a first sailing week, compare an inland-lake plan with a Wadden/coastal plan by exposure, approach complexity and available waiting options. Inland does not mean wave-free, while a coastal itinerary adds stream, entrance and sea-state questions. A Zeeland connection may mix tidal and managed basins. Select the route type first, then the applicable KNMI product and RWS information; country-wide sunshine is not the deciding metric.
- KNMI coastal waters, lakes and estuaries — Named Dutch sectors including IJsselmeer and Marken; read actual issue/validity.
- Rijkswaterstaat IJsselmeer water information — Official lake information and links to water data and waterway/lock notices.
Compare the boat with connections, not just the wind
Include vessel draught and dimensions, confirmed bridge/lock constraints and the relevant level reference when evaluating an itinerary. A good weather period cannot cure a mismatched connection or an unverified inlet. Keep waterway notices separate from the meteorological text. When a delay changes the final basin or arrival time, refresh the local source set rather than carrying the first station and forecast through the entire holiday.
- Rijkswaterstaat IJsselmeer water information
- Rijkswaterstaat Waterinfo — Water observations and forecasts; parameter, station and datum must be checked. Direct product verification is limited; obtain the current issue from the issuer.
- RYA passage planning — Practitioner guidance on contingency, tides, vessel and crew constraints.
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.