Picture from surfline.comUpon reading this article, the BS meter started red lining. Obviously the wave is just a wave and there was no mysterious wave suction zone happening, so what exactly was the problem ?The only two possible wave related factors were the speed of the board and the slope of the wave. the slope wasn't remarkable, but the speed could well have been.We immediately came to the conclusion that the problem was related to the speed of the board, and the fin setup. At the time we had been working for several years on 'hydrofoil' fins with horizontal wing area . We were very much aware of the powerful lifting forces produced by underwater foils and how these forces increase exponentially with increases in speed. We had also figured out ( which hadn't been mentioned in those days but which is now common knowledge ) that thruster tri fin setups have horizontal lifting area due to the cant on their side fins.So it became clear that what was happening at Mavericks was that the thruster side fins were producing powerful lift at the speeds achieved on a big wave drop at Mavericks. The lift produced by side fins increases exponentially with speed, it increases with the square as speed increases so if the rider is doing 35 mph at the base of the wave during the drop the lift produced by the fins is four times what it would be at 17.5 mph. Of course the effort which the rider can apply when turning is limited by their weight, which doesn't increase with speed. The result is that the rider's efforts become less and less effective as the board goes faster. In the case of the thruster side fins the toe in used complicates matters further as it has a braking effect on the board, as well as possibly turning the lift downwards . Toe in increases the forces produced by the fin , which in turn further reduces the relative power of the rider over the board.Our research with horizontal wing area lifting foils had shown that they can resist rail to rail rolling movements which are needed in order to turn the board. In short we had experienced the 'suction zone' effect with smaller waves and more lifting surface area. The problem increases when:1) The board goes faster2) The horizontal lifting area is closer to the rail and further from the centre of the board ( it has more leverage and thus resists rail to rail rolling more )3) The surfboard is riding with a nose down attitude. This tends to make it harder for the rider to get his weight over the fin area, further reducing the power the rider has over the lifting force of the finsSo the problem was that thruster setups which worked well in a given speed range were being used outside of their range. Toe in and cant with thruster ( and 4 fin) setups is speed dependent. Not wave size dependent but speed dependent.The solution we came up with with allowed us to keep horizontal lifting area while completely elininating the problem of the so called 'suction' whereby the fin takes over and prevents the rider from controlling and turning the board. Our solution is as perfect as it gets and is the half pipe tunnel fin. . . lots of lifting area and zero rail to rail resistance. The tunnel fin setup is not speed dependent in terms of handling. . .. because it offers zero rail to rail resistance the half pipe tunnel handles just as perfectly as speed increases. we have tested boards with half pipe tunnels at speeds up top 37 mph and their handling remains docile.. . . while the benefits of lift increase.During 2004 I wrote a long article about all this suction zone and lift area business, and suggested that the solution would be to use a tunnel fin , or to reduce side fin cant and toe in. I also suggested that a four fin setup would be an improvement over the thruster setup, but that the tunnel fin ( in line with a singlefin) would be the best solution of all as it allows the beneficial lift area to be maintained . . . the other solution, i.e. reducing toe in and cant, does away with the vertical lift.Because optimising side fin toe in and cant is specific to the speed range the board will experience, it isn't possible to make an all round surfboard with side fins. A 'gun' board will be too tracky and stiff in small waves, whereas a small wave board will get the problems described above. Half pipe tunnel fins on the other hand work perfectly well at any speed, if set up correctly and used on the right kind of surfboard .The visible response to my 2004 article was ridicule, ridicule, and a fair dose of anger from the Californians. To them, solutions needed to come from californians familiar with the break. .. . an understandable emotional knee jerk reaction. Miraculously however, the Mavericks guns started to use reduced toe in and cant, and the 4 fin setup became popular.The suction zone vanished without trace. . . it was a modern surfing myth !
The Myth of the Mavericks suction zone.
We mentioned this so called Mavericks 'suction zone' recently in passing, and had a question from a reader regarding what it is all about.Back in about 2003 or 2004 we read in Surfing magazine about a thing called the 'suction zone' at Californian big wave spot Mavericks. This was supposed to be a mysterious zone near the bottom of the wave which the riders were having trouble with where they would be unable to turn their boards and would get steamrollered by the wave as a result. The article showed a picture of Anthony Tashnick on a huge Mavericks wave, trying to turn his board, to no avail. Anthony appeared to be really trying to get a rail in, and had a desperate look on his face as he struggled to control his board. The wave at this point was not steep but still had fair bit of slope to it, so he wasn't on flat water.
Picture from surfline.comUpon reading this article, the BS meter started red lining. Obviously the wave is just a wave and there was no mysterious wave suction zone happening, so what exactly was the problem ?The only two possible wave related factors were the speed of the board and the slope of the wave. the slope wasn't remarkable, but the speed could well have been.We immediately came to the conclusion that the problem was related to the speed of the board, and the fin setup. At the time we had been working for several years on 'hydrofoil' fins with horizontal wing area . We were very much aware of the powerful lifting forces produced by underwater foils and how these forces increase exponentially with increases in speed. We had also figured out ( which hadn't been mentioned in those days but which is now common knowledge ) that thruster tri fin setups have horizontal lifting area due to the cant on their side fins.So it became clear that what was happening at Mavericks was that the thruster side fins were producing powerful lift at the speeds achieved on a big wave drop at Mavericks. The lift produced by side fins increases exponentially with speed, it increases with the square as speed increases so if the rider is doing 35 mph at the base of the wave during the drop the lift produced by the fins is four times what it would be at 17.5 mph. Of course the effort which the rider can apply when turning is limited by their weight, which doesn't increase with speed. The result is that the rider's efforts become less and less effective as the board goes faster. In the case of the thruster side fins the toe in used complicates matters further as it has a braking effect on the board, as well as possibly turning the lift downwards . Toe in increases the forces produced by the fin , which in turn further reduces the relative power of the rider over the board.Our research with horizontal wing area lifting foils had shown that they can resist rail to rail rolling movements which are needed in order to turn the board. In short we had experienced the 'suction zone' effect with smaller waves and more lifting surface area. The problem increases when:1) The board goes faster2) The horizontal lifting area is closer to the rail and further from the centre of the board ( it has more leverage and thus resists rail to rail rolling more )3) The surfboard is riding with a nose down attitude. This tends to make it harder for the rider to get his weight over the fin area, further reducing the power the rider has over the lifting force of the finsSo the problem was that thruster setups which worked well in a given speed range were being used outside of their range. Toe in and cant with thruster ( and 4 fin) setups is speed dependent. Not wave size dependent but speed dependent.The solution we came up with with allowed us to keep horizontal lifting area while completely elininating the problem of the so called 'suction' whereby the fin takes over and prevents the rider from controlling and turning the board. Our solution is as perfect as it gets and is the half pipe tunnel fin. . . lots of lifting area and zero rail to rail resistance. The tunnel fin setup is not speed dependent in terms of handling. . .. because it offers zero rail to rail resistance the half pipe tunnel handles just as perfectly as speed increases. we have tested boards with half pipe tunnels at speeds up top 37 mph and their handling remains docile.. . . while the benefits of lift increase.During 2004 I wrote a long article about all this suction zone and lift area business, and suggested that the solution would be to use a tunnel fin , or to reduce side fin cant and toe in. I also suggested that a four fin setup would be an improvement over the thruster setup, but that the tunnel fin ( in line with a singlefin) would be the best solution of all as it allows the beneficial lift area to be maintained . . . the other solution, i.e. reducing toe in and cant, does away with the vertical lift.Because optimising side fin toe in and cant is specific to the speed range the board will experience, it isn't possible to make an all round surfboard with side fins. A 'gun' board will be too tracky and stiff in small waves, whereas a small wave board will get the problems described above. Half pipe tunnel fins on the other hand work perfectly well at any speed, if set up correctly and used on the right kind of surfboard .The visible response to my 2004 article was ridicule, ridicule, and a fair dose of anger from the Californians. To them, solutions needed to come from californians familiar with the break. .. . an understandable emotional knee jerk reaction. Miraculously however, the Mavericks guns started to use reduced toe in and cant, and the 4 fin setup became popular.The suction zone vanished without trace. . . it was a modern surfing myth !
Picture from surfline.comUpon reading this article, the BS meter started red lining. Obviously the wave is just a wave and there was no mysterious wave suction zone happening, so what exactly was the problem ?The only two possible wave related factors were the speed of the board and the slope of the wave. the slope wasn't remarkable, but the speed could well have been.We immediately came to the conclusion that the problem was related to the speed of the board, and the fin setup. At the time we had been working for several years on 'hydrofoil' fins with horizontal wing area . We were very much aware of the powerful lifting forces produced by underwater foils and how these forces increase exponentially with increases in speed. We had also figured out ( which hadn't been mentioned in those days but which is now common knowledge ) that thruster tri fin setups have horizontal lifting area due to the cant on their side fins.So it became clear that what was happening at Mavericks was that the thruster side fins were producing powerful lift at the speeds achieved on a big wave drop at Mavericks. The lift produced by side fins increases exponentially with speed, it increases with the square as speed increases so if the rider is doing 35 mph at the base of the wave during the drop the lift produced by the fins is four times what it would be at 17.5 mph. Of course the effort which the rider can apply when turning is limited by their weight, which doesn't increase with speed. The result is that the rider's efforts become less and less effective as the board goes faster. In the case of the thruster side fins the toe in used complicates matters further as it has a braking effect on the board, as well as possibly turning the lift downwards . Toe in increases the forces produced by the fin , which in turn further reduces the relative power of the rider over the board.Our research with horizontal wing area lifting foils had shown that they can resist rail to rail rolling movements which are needed in order to turn the board. In short we had experienced the 'suction zone' effect with smaller waves and more lifting surface area. The problem increases when:1) The board goes faster2) The horizontal lifting area is closer to the rail and further from the centre of the board ( it has more leverage and thus resists rail to rail rolling more )3) The surfboard is riding with a nose down attitude. This tends to make it harder for the rider to get his weight over the fin area, further reducing the power the rider has over the lifting force of the finsSo the problem was that thruster setups which worked well in a given speed range were being used outside of their range. Toe in and cant with thruster ( and 4 fin) setups is speed dependent. Not wave size dependent but speed dependent.The solution we came up with with allowed us to keep horizontal lifting area while completely elininating the problem of the so called 'suction' whereby the fin takes over and prevents the rider from controlling and turning the board. Our solution is as perfect as it gets and is the half pipe tunnel fin. . . lots of lifting area and zero rail to rail resistance. The tunnel fin setup is not speed dependent in terms of handling. . .. because it offers zero rail to rail resistance the half pipe tunnel handles just as perfectly as speed increases. we have tested boards with half pipe tunnels at speeds up top 37 mph and their handling remains docile.. . . while the benefits of lift increase.During 2004 I wrote a long article about all this suction zone and lift area business, and suggested that the solution would be to use a tunnel fin , or to reduce side fin cant and toe in. I also suggested that a four fin setup would be an improvement over the thruster setup, but that the tunnel fin ( in line with a singlefin) would be the best solution of all as it allows the beneficial lift area to be maintained . . . the other solution, i.e. reducing toe in and cant, does away with the vertical lift.Because optimising side fin toe in and cant is specific to the speed range the board will experience, it isn't possible to make an all round surfboard with side fins. A 'gun' board will be too tracky and stiff in small waves, whereas a small wave board will get the problems described above. Half pipe tunnel fins on the other hand work perfectly well at any speed, if set up correctly and used on the right kind of surfboard .The visible response to my 2004 article was ridicule, ridicule, and a fair dose of anger from the Californians. To them, solutions needed to come from californians familiar with the break. .. . an understandable emotional knee jerk reaction. Miraculously however, the Mavericks guns started to use reduced toe in and cant, and the 4 fin setup became popular.The suction zone vanished without trace. . . it was a modern surfing myth !
