Grevelingenmeer

The Grevelingen was a sea arm between Schouwen-Duiveland and Goeree-Overflakkee until the Delta Works closed it at both ends - the Grevelingendam in 1965 and the Brouwersdam in 1971 - leaving about a hundred and eight square kilometres of enclosed salt water, the largest saltwater lake in western Europe. Without tides the water is clear and calm, which made it the principal Dutch diving destination: lobster, cuttlefish in spring, anemones and wrecks placed deliberately, with marked entry points along the shore and dive centres at Scharendijke and Dreischor. It is also a major sailing and windsurfing water. Cutting off the tide caused problems - oxygen depletion in the deeper parts and loss of the old intertidal life - and a sluice in the Brouwersdam has been debated for years as a way of restoring some exchange with the sea.

What you actually see

• The largest saltwater lake in western Europe - about 108 square kilometres, closed off in 1971.
• Clear tideless water - the reason it became the main Dutch dive site.
• Marked dive entries - along the shore, with centres at Scharendijke and Dreischor.
• Sailing and windsurfing - the open water used heavily in summer.

When to go

May to September. A day.

Honest expectations

Diving needs qualification and a local briefing - the entries have currents at the sluices. Deeper water suffers oxygen depletion in summer. The shore is exposed and windy. Facilities cluster at a few points.

Nearby

The Brouwersdam and the North Sea beaches are west; Zierikzee is south.