Windsurf Wave Foils
(Written April 2021)
Windsurf wave foiling is different than other forms of sailboarding. With traditional windsurfing the sailor is mostly concerned with matching the sail and board to the wind speed and water conditions. But with windsurf wave foiling we must also match the foil to the conditions. There are four main components of the foil that we must consider for windsurf wave foiling: front wing, rear wing, fuselage, and mast.
Front Wing - The front wing generates most of the lift. In general, larger wings generate more lift but have lower top end speed, while smaller wings generate less lift but have higher top end speed. Lower aspect wings generate more lift but have lower top end speed, while higher aspect wings generate less lift but have higher top end speed. Thicker wings generate more lift but have lower top end speed, while thinner wings generate less lift but have higher top end speed. Once you are on the water, the size and shape of your front wing remains the same, but the amount of lift can still change. What factors can change the amount of lift from your wing when you are on the water? Wind speed, wave speed, and wave steepness can all affect the amount of lift that is generated from your front wing. Let's examine these a little closer.
If the wind speed increases while you're on the water your board speed will likely also increase. This will increase the lift from you front wing. There are a few things you can do without coming back to the beach to re-rig. First, you could sheet out more. Moving your harness lines forward can help with this. Second, you could completely flag the sail out and just ride the waves. Third, you could move your feet forward to hold down the front of the board more. With windsurf wave foiling you will not have foot straps. This will allow you to take that step forward that you will need in overpowered situations.
The wave speed and wave steepness will also be important. Bigger waves move faster. You must also move faster in order to keep up with that wave. And bigger waves are generally steeper, which means you will move faster when going down the steeper waves. Therefore, you must again take a big step forward in order to hold down the front of the board.
At some point the wind speed and wave size may increase so much that you need to come back to the beach and re-rig. Start with the front wing. Match the front wing to the size of the wave. Big wings for small waves and small wings for big waves. Since you must go faster to keep up with a big wave use a smaller wing.
If the wind speed increases while you're on the water your board speed will likely also increase. This will increase the lift from you front wing. There are a few things you can do without coming back to the beach to re-rig. First, you could sheet out more. Moving your harness lines forward can help with this. Second, you could completely flag the sail out and just ride the waves. Third, you could move your feet forward to hold down the front of the board more. With windsurf wave foiling you will not have foot straps. This will allow you to take that step forward that you will need in overpowered situations.
The wave speed and wave steepness will also be important. Bigger waves move faster. You must also move faster in order to keep up with that wave. And bigger waves are generally steeper, which means you will move faster when going down the steeper waves. Therefore, you must again take a big step forward in order to hold down the front of the board.
At some point the wind speed and wave size may increase so much that you need to come back to the beach and re-rig. Start with the front wing. Match the front wing to the size of the wave. Big wings for small waves and small wings for big waves. Since you must go faster to keep up with a big wave use a smaller wing.
Rear Wing
Fuselage
Mast
