Aloha itsRobert Stehlik with blue planet surf I wanted to go over a couple of terms from is from
Aeronautics really but it's the angle of attack versus the angle of incidence really the angle of
incidence is kind of the built in angle of the foil so if you imagine a straight line running
through the fuselage and then of a line running through the foil from the tip to the tip here so
usually on the front wing is between one and three degrees on most foils and then the tail wing has
a opposite angles by pulling down on the back it kind of creates lift and when you're riding
it kind of automatically keeps going the back tail wing is usually also between one and three
degrees relative to the fuselage so that's the angle of incidence if the board is flat you want
that angle of incidence to be the same same way you don't want it to be way off like sometimes if
the if you have a lot of rocker and the tail of your board your your mass can be kind of tilted
backwards which means you have less angle of incidence so that means it might be harder to
take off or if it's kind of angled forward too much then that increases your angle of incidence
and then that way the foil will lift faster but it might also be harder to control because you
have to push the nose down more to kind of make up for that when you're riding when you're riding
what really matters is the angle of attack so and that's the relative angle to the water flow
so once there's water flowing over the foil it's that that's the angle of attack so the steeper
the angle of attack is on the water the more lift it's going to create and the slower you're
going basically the more you need to increase the angle of attack on the same size foil to keep it
going and then as you're going faster you kind of push the nose down to kind of decrease the angle
of attack if it's not very steep you can have the board kind of flat if the way it's really
steep you have to kind of follow the angle of the wave so if you know if you're on a steep wave you
actually your board has to be and a parallel to the surface of the water to keep that angle from
becoming too big otherwise the angle of attack if you have the board like this and the waves
like this is going to be a really steep angle of attack to the foil and you're just gonna shoot out
of the water and breach that's kind of one of the things that's that's tricky about foiling
especially for surfers because instead of being two-dimensional where you're on the water surface
and just going left and right on the foil the ads that hold the dimension of up-and-down so you got
the height of the foil flying up and down and the left and right turning it's like basically adding
a third dimension to the surfing and that can be kind of hard to hard to figure out for beginners
the real simply put is the angle of incidence is the static angle the way it's designed like the
fuselage is straight then you got the angle of the front wing and the angle of the back wing and the
90 degrees mast and then the shape of the board but once you get in the water angle of attack is
the angle of the water flow to the foils you're taking off on a steep wave your foil has to be
follow the contour of the wave so the steeper the takeoff is the more you have to be leaning
on your nose that's why it's really hard to catch a big steep wave on a foil because basically you
have to have your nose pointed straight down so in that case what I usually do is I try to
go for the shoulder try to get away from that steep part of the wave if possible and write
it along the shoulder because once you get that angle of attack too steep the oil just breaches
and you crash following the contour of the wave is real important to keep that angle of attack
in this smaller range Sam always says if I ride low and in control so that means is keeping the
foil underwater don't come up too high you don't get the oil too close to the surface keep that
angle of attack fairly low so you don't create too much lift too quickly where the foil shoots
out of the water and just breaches and that's probably one of the hardest things to learn at
first is keeping the foil in the water keeping the board and control and keeping it low to the
water come up slowly and then keep it there I hope that helped thanks for watching Aloha