Bridges and locks: opening times, clearance and planning

Fixed bridges: clearance and mast height

At a fixed bridge only height matters. Charts and pilot books give the clearance, in tidal waters relative to a stated water level. If the water is higher, at spring high water or in a storm surge, there is less room. Measure your air draught including antenna, wind instrument and light, not the mast length from the brochure.

Fixed bridges change too: the Fehmarnsund Bridge normally gives 23 m of clearance, but because of a suspended scaffold only 18 m until the end of 2026 (BfS 101/26, a German notice to mariners). If your mast is taller, sail round the outside of Fehmarn.

Opening bridges

Bascule and swing bridges open at fixed times, on request within time windows, or not at all, depending on season, day of the week and public holidays. When closed, they have a clearance under which low boats can pass without an opening. Two examples on the Schlei:

• The Kappeln bascule bridge opens on request from April to October 20 minutes before every full hour, from 05:40 to 21:40, for 15 minutes at most each time. Closed, it has 3.3 m of clearance.
• The temporary bridge at Lindaunis opens eight times a day in the 2026 season, on the half hour from 10:30 to 17:30. From November to March the construction site is closed to navigation.

Allow a buffer: if you narrowly miss an opening, you wait for the next one, in the evening often until the next morning. Wait clear of the fairway and only go through when the bridge is open and the signals allow it.

Locks

In a lock you are raised or lowered between two water levels. For planning, what counts is the operating hours, the waiting time and how long the locking takes. Have lines and fenders ready on both sides, call in as required by VHF or telephone, and follow the light signals and the lock staff. Some harbour locks on tidal coasts only operate around high water, see Tides and tidal streams.

The Kiel Canal

The Kiel Canal (Nord-Ostsee-Kanal, NOK) links the Elbe at Brunsbüttel with the Kiel Fjord at Kiel-Holtenau. According to the leaflet from the WSA Nord-Ostsee-Kanal, the federal waterways office that runs the canal, the following applies to pleasure craft:

• Passage only during the daylight passage hours and not in restricted visibility. The hours change every half month: at the beginning of January 07:30 to 17:00, from June to mid-July 02:30 to 22:00. The table is in CET; in summer time it applies one hour later. Before the daylight hours end, head for a mooring such as Gieselau, the Obereidersee or the Flemhuder See.
• Sailing is prohibited on the canal; if you motor-sail, hoist a cone point down.
• Pleasure craft lock through together with commercial shipping, and waiting plus locking usually take around an hour in total. At Kiel-Holtenau, pleasure craft currently use the large chambers because the Small Lock is being rebuilt.
• Monitor VHF 13 at the Brunsbüttel locks and 12 at Kiel-Holtenau, and channels 2 and 3 under way.
• In 2026 the canal dues for the full transit are 12 to 43 euros depending on length; they will be abolished on 1 January 2027.

Netherlands, Belgium, France

In the Netherlands, the Staande Mastroute (standing mast route) runs through the inland waterways with the mast up, via many opening bridges; through Amsterdam it goes only at night in convoy. Operating times change with the season, public holidays and construction work. Current times and closures for locks and bridges in the Netherlands, Belgium and France are listed on the European inland navigation portal EuRIS.

German coast: notices to mariners

Closures of bridges, locks and storm surge barriers on the German coast are published by the Federal Waterways and Shipping Administration as Bekanntmachungen für Seefahrer (BfS, notices to mariners) on ELWIS. Read them before you pass through the Kiel Canal, the Eider or the Schlei.

How Sailseer plans bridges and locks

• The route checks fixed bridges against your mast height plus a 0.5 m margin. If one is too low, it looks for another way. It does not take the current water level into account.
• At opening bridges and locks it works with your arrival time: clear, open, wait for the next opening, closed or too low. Waiting times push back the following legs, and the departure windows show them.
• The times come first from hand-checked operator information (for example the Kiel Canal, the Eider, Kappeln, Lindaunis, Hvide Sande), then from EuRIS for around 500 locks and opening bridges in the Netherlands, Belgium and France, from Rijkswaterstaat's operating times and from OpenStreetMap. “Commercial traffic only” counts as closed for pleasure craft; “by prior notice only” is shown at the passage.
• On the German coast, Sailseer reads the BfS from ELWIS every three hours for around 40 structures from Kappeln via the Kiel Canal to Emden. It includes confirmed closure times; uncertain ones (“eventuell”, “ca.”, meaning possibly or approximately) are shown as a note.
• Where no source has times, the assumption 06:00 to 22:00 local time with 30 minutes per locking applies, and the page says so. Check with the operator beforehand.
• The route avoids an opening bridge with no opening times at all for boats with a mast, and a structure closed on the day of departure for every boat.
• On inland canals and rivers, fixed bridges without a known height are assumed to have 3.5 m of clearance. With “Mast lowered”, the height above the water counts and the boat travels under engine.
• Sailseer calculates fees by boat length where the tariff is known, for example on the Kiel Canal, the Caledonian Canal and the Ems-Jade Canal.

On the map, every bridge and lock has a popup with height, today's and tomorrow's times, notes, source and, where known, VHF channel and phone number. If you are crossing a border, you will find the formalities in the guide Clearing in.

Opening times change at short notice and structures break down. Sailseer is not intended for navigation: the notices to mariners, the signals at the structure and the instructions of the staff are authoritative.