In English boats dry out and do not 'fall dry' (Dunglish) The term 'dry out' is also used abundantly for moorings where the boats come to rest on the sea bottom when the tide is out.

http://www.boatbiketours.com/profiel.asp?steID=5&item=1605
The Waddenzee is the major wet natural reserve of North-western Europe. The western part of the Waddenzee is part of the sailing area of our sailing ships. The port of Den Oever is favourably situated on the western end of the Afsluitdijk. The dike has a lock here: therefore the IJsselmeer can be reached very well. At low tide the Waddenzee changes into a unique landscape of small pools and sand flats, on which the ships with their flat bottoms – as long as nature isn’t harmed - can dry out, enabling passengers to literally walk on the bottom of the sea. With a bit of luck you may see a family of seals on a nearby sand flat. After a few hours the fun is over and the sea returns to its original form: a unique experience! The western West Frisian Islands are very much worth a visit.



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Note added at 10 hrs (2008-04-08 07:12:34 GMT)
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http://www.helfordrivermoorings.co.uk/local.htm
Ideally, for a first visit, arrive just after LW when all the hazards are easy to see, and feel your way in on the tide, anchoring clear of the local moorings off the houses at Flushing if you can, or go further into the creek to the picturesque hamlet and church at St Anthony, where you will dry out, well tucked away in this hidden corner. Here, on the shingly foreshore is the small yard of Sailaway St Anthony (Tel: 01326 231357) - they might be able to provide a mooring.

Swinging Moorings
http://www.dartharbour.org/moorings-moorings-policy/swinging...
With this mooring, the vessel is tied to a buoy, which is itself attached via a chain or rope (known as a riser) to a weight, or anchors on the fundus (riverbed). The arrangement allows the vessel to move so that it will head into the wind or the tide – whichever is the stronger. In summer, when the weather is not adverse it is common for visitors to ‘raft up’ on such berths i.e. several boats on the one mooring. Such moorings may be in deep water or drying out, sometimes known as mud berths.