Diving in the Netherlands

The Netherlands may not be the first destination you would think of when you are planning your next diving vacation. But there are a lot of possibilities for a diver in this small country. Every year thousands of mostly Dutch, Belgium, German and French divers travel to this northern European country to have a combination of diving and Dutch culture.

There are many interesting places for a diver in the Netherlands. The main dive sites are all located in the province of “Zeeland”, which is located in the south west of the Netherlands. There you can dive in the “Grevelingen”, a salt water lake where there is no current. Or you can decide to go to the “Oosterschelde”. The “Oosterschelde” still has an open connection with the North Sea, so there can be quite some current there. Other possibilities are of course the North Sea or one of the fresh water lakes that are abundantly available.

A large part of the country lies below sea level. This fact has always played an important role in the history of the Netherlands. The dikes and bridges made by the dutch are famous around the world. The struggle against the sea has played a very important role in the origin of the current dive sites in “Zeeland”. In 1953 the dikes broke in “Zeeland” after a very high tide combined with a big storm. This killed over 1800 people. This disaster would have been much bigger if there hasn’t been a brave skipper who sailed his ship into a hole in the dike in Nieuwerkerk aan den IJssel. This catastrophe still lives in the mind of many Dutch. After this disaster the decision was made that this should never happen again. This resulted in the famous “Delta werken”, a series of extremely large water controling projects. The last project of these “Delta werken” has just been finished a few years ago.

As a result of this these projects the water of the “Grevelingen” was completely closed of from the sea. This closure originally meant that no sea water could enter the “Grevelingen”. This closure caused the water becoming less salty. The underwater life could not adjust to this new environment resulting in a rapid decline of the number of aquatic species in the “Grevelingen”. The original underwater world was threatened to be destroyed. To overcome this negative result of the closure a flood-gate was placed through which salt water could enter the “Grevelingen.” The flora and fauna recovered after this measure. The final result is a very accessible, easy to dive lake, where a lot of animals live that you normally would see in waters with an open connection to the North Sea.

The disaster of 1953 also had a large impact on the “Oosterschelde”. The first idea was to completely close-off this sea arm from the North Sea, just as was done with the “Grevelingen”. This original plan resulted in a lot of protests from environmental movements. These protests resulted in a change of plans for the “Oosterschelde”. No fixed dam would be build. The alternative is found in the “Stormvloedkering”, which consists of concrete columns that rest on the floor of the “Oosterschelde’. Between these columns big sliding lids are placed. These sliding lids can be closed in times of a very high tide which closes of the “Oosterschelde” from the North Sea. The result was a dam where the water can pass trough. At that time it was considered a true miracle.

Thanks to the “stormvloedkering” the “Oosterschelde” remained fully connected to the North Sea. At times of normal weather the sliding lids are open resulting in a tidal movement. The sliding lids are only temporarily closed in times of extreme storms or very high tides.As a result fresh water from the North Sea can enter the “Oosterschelde” twice a day. The result of all this is an ideal environment for many birds, fish and all other animals that prefer a salt water environment with current. In 2002 the “Oosterschelde” was proclaimed a National park due to the unique environment of the “Oosterschelde”.

The “Deltawerken” also had another positive effect on the aquatic life in “Zeeland”. The dikes surrounding the “Grevelingen” and “Oosterschelde” were heavily strengthened. This was done by sinking enormous amounds of basalt and concrete blocks at the base of the dikes. The concrete blocks can measure up to 1 meter. These results of this work can be found everywhere underwater. This new hard habitat gives home to a lot of animals that need a hard substrate to live on.

A few years ago some artificial reefs where created in the “Grevelingen” to further encourage the development of aquatic life. These reefs consist of big hollow concrete balls with big round holes in them, the so called reefballs. These artificial reefs are now fully populated by crabs, lobsters, starfish and other animals that live in the “Grevelingen”. The reefs are all created on dive sites with a good accessibility for divers.

Both the “Oosterschelde” and the “Grevelingen” are fit for a nice dive. In the “Oosterschelde” it is only possible to dive on of the four dead tide times of a day. On other times the current is much too strong to dive in the “Oosterschelde”. Only experienced “Zeeland” divers know where to dive safely when there is much current in the “Oosterschelde”. The diveshops in Zeeland can exactly tell you at which times it is absolutely safe to go diving in the "Oosterschelde”. All of these shops provide free time tables containing the dead tide times for every day of the current year. Diving in the “Oosterschelde” is safe when you go in on the right time, but bear in mind that most dive sites are not suitable for real beginners. The “Grevelingen” has no tidal current, making it ideal also for all divers, also the divers with very little experience. Here you can safely dive on every time of the day.