The Fence Wade is a very adaptable technique that really takes advantage of river features and eddies that are formed by waders.  Picture getting 6 people quickly across a shallow fast stream.  The first person ventures a couple feet from the shoreline and grabs a stable position.  The next uses the eddy behind him and plants himself fairly close by next to him (we now have two eddies).  Keep up this process with the remaining 4 persons and we have a nice long fence.  Now the first person can go behind the other 5 and set-up next to the sixth person.  A group of paddlers can quickly leap frog across swiftwater in this manner.  If there are natural eddies along the way, they become an extra person - no value in placing a fence post there.  When traversing the fence, you can use the others as a hand rail for extra stability.