Thanks for link to patent.

I did not find "the" patent.
Just did a quicky search for the named inventor.
There were more than one that matched for Stephen S...

go to uspto.gov
pick patent search
pick advanced search
use the "in/" specifier to formulate a boolean search that includes the named inventor

also, the Wikipedia "Wave Power" page has a reference to the original 1976 patent for the Duck credited to just Stephen Salter.