George Greenough’s Edge Board description 1969 to 2016
The Edge Board design by George Greenough first came about in the late 1960’s. The surfboard he had used up until that time was designed for perfect conditions with no crowds. As the population in the water increased he was forced to go to the grade “B” spots. Those types of breaks have lots of dead spots in the wave that a board with a rounded bottom is unable to skate across. Since George has an extensive background in boat design he created a new board that had a full displacement bottom around the outside of the board to handle rough conditions and choppy seas while the center of the board had a very high speed concave section surrounded by a very hard edge. This new design allowed him to perform in rough conditions and still maintain a high degree of speed especially through the flat sections of the wave. Although this design stirred up mild interest during the 1970’s it was very complex and not easily translated into a standup surfboard. Simultaneously the 3-fin surfboards were being developed along with the professional surfing circuit and the sport had taken a different direction altogether.
As crowding in the water continued during the 1980’s, George took to the open ocean on the wind powering his 7’3” edge bottom sailboard made out of carbon fiber. For many years he continued to out perform in speed and maneuverability the best of the open ocean sailors and even was at the top of his age and weight class in competition. The design itself proved to be superior to a regular flat bottom board. Then one day in the early 90’s while he was sailing in very large open-ocean waves, George rode what he believes is the largest wave of his entire life. During this ride he dropped into a wave that was so large that it shut the wind supply off of his sail as it was blocked from the wind by the back of the wave. He rode this massive wave standing on his 7’3” board with no wind in the sail and surfed it like a conventional surfboard. During this ride he was able to extend his turns longer and faster with no loss of speed through the flat spots that any experience he had on any other type of board. It was after this life-changing day and he realized that his board in extreme conditions should be the highest expression of design for speed in large waves in existence. Unfortunately this extra ordinary single fin craft remained in relative obscurity for another decade until George decided to recreate some boards with the same design and have surfers try them for themselves. It is well documented in The Surfers Journal that Dave Rastovich rode one of these boards in Fiji and had a life changing experience on it. With no effort he was able to trim across the entire wave at such a high speed that after he pulled out he still coasted an additional 100 yards!
George explains that wetted surface increases drag. Since the narrow concave center of the board is five inches narrower than the outside dimensions, you have what is essentially a small hydroplane board underneath your conventional standup surfboard. Therefore with moderate speed the entire board will lift up out of the water and start planing on the much smaller footprint of the center plane thereby reducing the drag due to the small center plane. An additional benefit of the hard edges around the center plane combined with the rails of the board lifted all the way up to the deck is that you gain additional holding power. The board’s fin can have a 25% smaller area, which also contributes to greater speed. (Less wetted surface on the fin too.) After observing the performance of many contemporary big wave boards, which seem to lack ability to draw speed once they reach the bottom of the wave, George feels that this particular design will be very well suited for large surf. The reason being that the very straight narrow toe board will not slow down once you reach the bottom of the wave but will continue to run allowing you to cover more distance than a board that has tail rocker and multiple fins, both of which creates drag.
In my personal experimentation, I find that this design can be added to any conventional board that you are accustomed to riding and it will give you the added dimension of extra speed over the flat spots of the wave. I have experienced extra speed that I have never felt on any other boards which can come in handy when conditions call for it.