The Wadden coast is entirely within the range of the tidal wave entering the North Sea from the north. It turns out that in the Wadden Sea region, the reversal of the direction of the tidal currents, the turnaround, roughly coincides with the time of high and low water. The speeds of ebb and flow currents decrease inward. Due to the stronger flood current, the duration of the flood in the Wadden region is shorter than that of low tide. So one has to take into account fairly fast rising water on the mudflats.
Spring tide: If the sun and moon are in line with the earth, a maximum amplification of the attraction on the earth occurs. It is then Full Moon or New Moon, the tide is called spring tide and is characterized by a higher high water level and a lower low water level than normal. If the spring tide coincides with a storm, exceptionally high water levels can be achieved.
Dead tide: If the earth-moon connection line is perpendicular to the earth-sun, this is called the first quarter or last quarter. The associated tide is called dead tide, which has a lower high water level and a higher low water level than normal, so that the tidal difference is smaller. In reality, the wave character of the tides delays, so that spring tide and neap tide do not exactly coincide with the phases of the moon, but occur a few days after.
When is the spring or neap tide? It is spring tide and neap tide twice a month: spring tide about 3 days after Full Moon and after New Moon and neap tide about 3 days after First Quarter and after Last Quarter. If it is spring tide today, it will be dead tide in a week and vice versa. The tidal difference on the tidal flats is between 1.2 m (dead tide Den Helder) and 3.3 m (spring tide Delfzijl): from west to east the decline is increasing. In the Wadden region, the differences between spring tide and dead tide compared to average high water are in the order of 50 cm.
Sailing on tidal water
Sailing on the Wadden Sea is influenced by the current: depending on your day program and course, you can make use of the sea current by sailing with the current and thereby making your journey faster. Often, however, you have to deal with parts of the tour where you have the current against – or side current that puts the ship on side. The speeds of tidal currents can be quite high on certain parts of the mudflats, such as in the sea channels and the narrow deep channels near the sea: up to 4 knots (more than 7 km / hour). Flow rates of 5 or 6 knots do occur on the Eems and the German Wad. However, our ships have sufficient engine power to run against the current if necessary.
How do you know which way the current runs? There are a few simple facts that generally indicate when which current is flowing. For example, there are tidal tables that indicate where the high and low water are at a given day and time. You also know that at Texel, Terschelling, Ameland and Schiermonnikoog the flood flows in from the North Sea, so from low tide at Texel or Terschelling you sail with the current to, for example, Harlingen. Conversely, you sail with the current from Harlingen from high water to the islands. But there are also detailed maps of the mudflats that indicate at what time and in which channel the expected current and direction is. You must also take into account that the expected numbers may deviate due to the wind and the tide (spring or neap tide).
Falling dry on the Wadden Sea
Because our beautiful historic sailing ships have a flat bottom (draft Noordvaarder = 1.30m / Victoria S = 1.10m), they are ideal ships for falling dry. This is a unique experience not to be missed during the sailing trip on the Wadden Sea. We use the tide when it dries up. A few hours before low tide we sail onto the ship on one of the many sandbanks with outgoing water. The time depends on how much water drains and returns at high tide. We know from our years of experience where the most beautiful sandbanks are. Once stuck we wait until the water sinks further until we can get off the ship and explore the bottom of the Wadden Sea. We then walk on the seabed, where we previously sailed. Due to the fact that the Wadden Sea is a UNESCO World Heritage Site, we must not be allowed to run dry everywhere and we must adhere to the Wadden Code of Honor so as not to disturb nature (benthic animals, birds and seals). We inform our guests about this. We will board again when the water rises. When the ship comes back smoothly and floats, we sail – depending on weather, wind and time – to the port or anchor in a shipping channel. On board we have various search cards and booklets to look up what you have found. Of course we also go on the Wad with you and we are happy to share our knowledge. If there are cockles, mussels or shrimps, we can prepare them together and enjoy a tasty snack from the Wad.