The Dutch Wadden (Sands and Swatchways).

Next, to a dozen or so uninhabited and prohibited islets, the northern coasts of The Netherlands are protected by five real islands. From west to east, they are named Texel, Vlieland, Terschelling, Ameland and Schiermonnikoog.

These islands form part of an uninterrupted chain right up to Esbjerg in Denmark. It is a fascinating sailing ground, enough to last you a lifetime. There are no rocks anywhere, and the sandy bottom is interspersed with mudflats, swatchways, shingle and slime. You share this vast tidal estuary with birds, molluscs, crabs and seals. It is both a national reserve and an international heritage location.

All islands have tidal access from the Frisian or Holland mainland. Texel, Vlieland and Terschelling can be entered at any stage of the tide, Ameland en Terschelling two to three hours before and after local high water due to a wantij (uncovering shoal) that has to be passed.

Sailing across the shoals is a great experience, but not for the faint of heart since most of the area dries out at low water. Even the buoyed channels are none too easy: currents are well up to 3 knots, and it is not advisable to go against them. Since distances from the mainland are considerable, it is seldom possible to have a favourable tidal stream all the way or to avoid negotiating a wantij. This is why a prudent navigator keeps to the well-established practice to start sailing on hours determined by high water in a port of reference.

A few examples, just to start.

To                                From                            Start

Texel                           Den Oever                   0 – 3 hrs after HW Den Oever

Vlieland                      Harlingen                    2 hrs after        HW Harlingen

Terschelling                Harlingen                    2 hrs after        HW Harlingen

Ameland                      Harlingen                    2 hrs before     HW Harlingen (rush: shoals in midway!) Schiermonikoog      Lauwersoog                 30 min before  HW Lauwersoog

Harlingen                    Kornwerderzand         4 hrs before     HW Harlingen

For a comprehensive review, see http://www.watersportalmanak.nl/artikel/vertrektijden-jachthavens. In Dutch, but very easy to understand.

Den Oever is a tidal harbour directly connected to the non-tidal IJsselmeer. Name of adjacent locks: Stevinsluizen, open 24/24, tel 088 7973302 (call in winter or at night).

Harlingen is a tidal harbour in its own right, two hours from the locks at Kornwerderzand. Name of locks: Lorentzsluizen, open 24/24, tel 0517 578170 (no need to call). The Harlingen harbour has no locks, but the bridges will not open at night. You can wait in the outer harbour, however.

Lauwersoog is a tidal harbour giving access to the non-tidal Lauwersmeer (a two day inland trip from the IJsselmeer). Name of locks: Robbengatsluis, open in summer weekdays incl sat 0700-1900, sun 0800-2000, tel 0519 34 90 43.

The five islands together recently have set up an excellent website, aimed at the cruising sailor. You can spot the availability of berths per island (although you cannot make a reservation) in various length brackets. You will find prefered starting times for many trips around or over the shoals. There is a four-day weather forecast, and as an added benefit you can find here the times of local HW and LW. Handy of you must decide whether or not you can reach Schiermonikoog or Ameland, and no trouble with secondary ports calculations. Just take an hour or so familiarizing yourself with Dutch maritime expressions, and off you go. A few hints: meer vertrektijden means more preferred times to leave, and a red box means no berths available. http://www.waddenhavens.nl/index.php?option=com_harbour&view=default&Itemid=2

Charts

You will need four charts for the whole area: Noordzeekust, IJsselmeer, Waddenzee West and Waddenzee Oost. IJsselmeer will get you through a number of years, but the other charts must be renewed every year.

Al’s charts are published by the Hydrographers Office, they all cost 31.50 Euro, and they are widely available online or through chandlers. Both Waddenzee charts tend to be sold out quickly once they are published, usually in May for the current year.

Noordzeekust:             1801

IJsselmeer:                  1810

Waddenzee West:        1811

Waddenzee oost:         1812

Entering from the north

Of course, one can negotiate the islands from the north as well – from the open sea. Great care is to be taken in inclement weather, however: you need the incoming tide since the streams are very strong, but you must not have the wind against you – the breakers would be short and massive, the sand is very hard, and there is no turning back. Do not try this in anything over an F6. The wind might change, you might miss a buoy, or you might not have enough speed to get in before the tide changes direction. And of course, be sure to have an up to date chart.

This said, two islands are relatively easy to reach from the open sea: Texel and Terschelling. For Texel (Oudeschild) you will need the young local flood, but as the tidal stream is very strong you should make it with ease. Just carry on full speed. For Terschelling (West), the harbour entrance is not far from the fairway. It is advisable to come in on the young flood as well, but you have more time here as the distance from the open sea is less. Part of your way will be against the current no matter what, but this is inside the shoals and no breakers should develop.

Buoyage

Next to lateral and occasional cardinal buoys, most of the drying channels are marked by withies – pricked in Dutch. These are essentially witches’ brooms stuck in the sand. An open broom means red, a closed broom means green. In principle open (red) means port coming in, but since the channels twist and turn all over the place and might lead to or from a number of harbours, there is no easy way to tell left from right. Moreover, after a wantij, the withies normally change direction. A recent chart is essential. Never ever make the mistake to be smarter than the next buoy or withy – just sail from one to the other and tick off.

You will see pleasure craft anchored before a shoal waiting for it to open, and this is a very enjoyable way to spend an afternoon. With luck, you might negotiate two wantijen in one tide, but not three unless you go full throttle on a speedboat. Which is both to be frowned upon and illegal.

Do not confuse the withies with sticks used by mollusc fisherman to denote their farm area – they look remarkably similar, especially against the sun. They might not be amused finding you stuck in the middle of their precious farmland.

Drying out

Putting your ship on the sand or in the mud is a traditional way of spending the night or the day. Moreover, you save on the not inconsiderable marina cost. As the seabed is usually a combination of sand and mud, you often have the choice. Sand is harder and cleaner, but mud is easier when you have a keel stump. Of course, you need a retractable keel, a flat-bottomed ship, struts or a multihull. Ask around where drying out is allowed – there is a complicated protocol describing where and when what can be done, but this is impossible to explain in a few words. The best way to the novice is: look out for locations where you see ships anchored or dried out, and join these. The Koffiebonenplaat (coffee bean shoals) east of Terschelling and the shoals next to the harbours of Vlieland, Ameland and Schiermonikoog are classics. Be sure to have an anchor out toward the deep side channel (you can do this easily once the shoals have dried), so you can pull yourself off when the tide comes in again. And never touch bottom before the tide is well on the fall – say two hours after local HW. What goes down must come up eventually, but realise there might be a considerable variation in tidal heights even in one day. Usually, the amplitude of the morning tide is the most articulate one, which of course is fortunate should you get neaped on an evening tide. You might still get off the next morning. If not, relax and enjoy it.

Tidal heights and streams

With practice, you can do your sums on the basis of a detailed chart and the HW and LW predictions in any nautical almanack. Or get them for free at https://www.rijkswaterstaat.nl/water/waterdata-en-waterberichtgeving/waterdata/getij/index.aspx

Take care however that Dutch charts and tidal tables can be based on HW in a number of different ports of reference. It is very easy to get this mixed up. Also, not all tidal height predictions are based on LLWS or LAT as used in nautical charts. In many cases NAP is used instead (Nieuw Amsterdams Peil – an artificial inland water level used all over the Netherlands that needs to be translated into data compatible with nautical charts and is too complicated to discuss here). Always write down your calculations and double check everything. And while sailing, tick off every buoy on your chart or in your log. Stick to the main channels when you get started, and get acquainted with the system. In a week or so you will be sailing around like a native.

For tidal streams, the (hourly) Tidal Streams Atlas is the way to go. You can buy it in any nautical shop, but the Dutch canoe society provides us with a free copy. See http://www.wadkanovaren.nl/stroomnl.html. For the legend: HW is high water, VOOR means Before, NA means After. As an example, you can see that the best time to start your trip from the Kornwerderzand locks to Harlingen is HW Harlingen minus 4 hrs. Gives you four hours before the tide turns against you.

As a comprehensive alternative, the yearly HP33 guide issued by the Hydrographic Service gives both the tidal heights by the hour for every day of the year plus the direction of the tidal streams. This, of course, does away with any sums, although the prudent mariner would be well advised to meticulously plan his trip given his speed. Get your HP33 as a book at any chandler or in digital form (HP33D / NLTides 2018). The digital version has more info but is less easily readable.

Rob Boonzajer Flaes

The opinions expressed in this article are the author’s own and do not reflect the view of noonsite.com or the World Cruising Club.