Apparatus for creating a local reduction in wave height

Abstract

Apparatus for creating a local reduction in wave height comprises a buoyant or semi buoyant top surface portion ( 20 ) with drag inducing elements ( 26 ) disposed below said portion. The drag inducing elements ( 26 ) may be compressible or inflatable and collapsible. The apparatus is especially suitable for temporary usage at a given site, after which is may be transported to another site or stored. The compressible or collapsible nature of the drag inducing elements ( 26 ) facilitates transport and storage by minimising the volume of the apparatus when not in use.

1 - 16 . (canceled)  
     
     
         17 . A deployable apparatus for creating a local reduction in wave height, the apparatus comprising at least one mat-like structure including: 
 a buoyant or semi-buoyant upper surface portion operatively disposed at or near the water surface; and    a plurality of drag inducing elements disposed below the upper surface portion, wherein the elements are collapsible or compressible when the apparatus is not in use.    
     
     
         18 . An apparatus as claimed in  claim 17 , wherein the upper surface portion comprises a plurality of flexibly linked buoyant or semi-buoyant sections.  
     
     
         19 . An apparatus as claimed in  claim 17 , wherein the upper surface portion comprises a single sheet of flexible buoyant or semi-buoyant material.  
     
     
         20 . An apparatus as claimed in  claim 17 , further comprising a plurality of flexible fluid retaining structures disposed thereon.  
     
     
         21 . An apparatus as claimed in  claim 20 , wherein the flexible fluid retaining structures comprise a network grid of pipes or tubes.  
     
     
         22 . An apparatus as claimed in  claim 20 , wherein fluid is maintained in the flexible structures under pressure.  
     
     
         23 . An apparatus as claimed in  claim 20 , further comprising at least one pump for supplying fluid to said flexible fluid retaining structures.  
     
     
         24 . An apparatus as claimed in  claim 22 , wherein the fluid is water.  
     
     
         25 . An apparatus as claimed in  claim 17 , wherein at least one of the drag inducing elements comprise shaped elements formed from a compressible material.  
     
     
         26 . An apparatus as claimed in  claim 17 , wherein at least one of the drag inducing elements comprise collapsible drogue anchors.  
     
     
         27 . An apparatus as claimed in  claim 17 , wherein at least one of the drag inducing elements are inflatable with an inflating fluid.  
     
     
         28 . An apparatus as claimed in  claim 27 , wherein the inflating fluid is water.  
     
     
         29 . A deployable apparatus for creating a local reduction in wave height, the apparatus comprising at least one mat-like structure including: 
 a buoyant or semi-buoyant upper surface portion operatively disposed at or near the water surface;    a plurality of drag inducing elements disposed below the upper surface portion, wherein the elements are collapsible or compressible when the apparatus is not in use; and    a plurality of flexible fluid retaining structures disposed thereon the apparatus,    wherein inflating fluid for the inflatable drag inducing elements is supplied from the flexible fluid retaining structures.    
     
     
         30 . An apparatus as claimed in  claim 29 , wherein the leading end of the apparatus is inclined downwardly with respect to incident waves.  
     
     
         31 . A system for deploying and recovering an apparatus for creating a local reduction in wave height comprising: 
 an apparatus as claimed in claim  1 ;    a deployment vessel;    a storage device on the vessel for the apparatus; and    means for paying out and recovering the apparatus.    
     
     
         32 . A system as claimed in  claim 31 , wherein the storage device is a storage reel about which the apparatus is wound when not in use