This question has and is plaguing a lot of intermediate level windsurfers. It gets a lot of debate thrown at it and is often given as the reason for some maneuvers not working or the windsurfing experience being unpleasant. Let me try to shed some light on the matter.
There are mainly two reasons for which we might put the mast-foot further forward or backward. Both are related to board handling. Here they are:
1. Beginner to intermediate planing: up until the point where we are just getting the hang of planing, the mast-foot position will determine how easy it will be for is to bear away from the wind and how much effort we have to put into going on a closed haul. The further forward the mast-foot is, the further forward the whole sail will be, and with it the sails pressure point. By moving the mast foot forward we are in essence moving the sails pressure point away from the fins (or skegs) pressure point which makes it easier to bear away from the wind. This is a good trick for those who have trouble with the board turning into the wind when they get into the foot-straps.
2. Advanced (fast) planing: once we are planing at high speeds we will be at a level where we no longer have to make use of small adjustments to the mast-foot position in order to get going or feel comfortable while sailing. At that point we need to find the position which give the most speed and the most control for the conditions. When we position the mast-foot towards the back we are able to get more speed (at least according to slalom racers, I still haven’t found the physical explanation for this) whilst the further forward we position the mast foot, the more control we have over the board as the pressure of the sail is transferred into the board further forward, keeping the nose down. Therefore, on flat water the mast-foot will do better more towards te back whereas in choppy conditions, putting the mast-foot further forward will provide us with more control.
We shouldn’t forget that these are only guidelines for gaining more control over the kit when sailing. Our size will also have an impact on where we will feel the most comfortable so try out different positions for each sail size in different water conditions and see which is the one that offers you the most enjoyable windsurfing experience.
I hope this helped. Let me know your experiences with testing various mast-moot positions.
But pushing the mast-foot forward will make the rig lean more backwards when going into the straps. Will this not make the board turn into the wind?
That is correct if you are not planing. However, once you get in the straps you have to lean on to the mast foot anyways to stop it from turning into the wind. This is the case regardless of where the mast foot it. For more on this technique you can check out my article on footstraps: howtowindsurf101.com/footstraps
Hope it helps 😉
I think when you put the mast foot backward, the board goes faster because the contact surface with the water (friction) is lesser.
Good point!
With the mast foot forward, it is easier to keep the board flat, especially for intermediates, hence easier and earlier planing at the expense of top speed and more difficult gybes. Works better in low winds or low skills. Added benefit is better upwind performance.
One thing I learned is in stronger wind you move it forward since the rig is leaned back more essentially to compensate for the position of the centre of effort on the sail. It’s a matter of keeping the weight of the sailor balanced with the force exerted on the sail.
Where you set the mast foot depends on what sort of board you are on.
On a waveboard you should stick the mast in the middle of the track and leave it there. When wave sailing you need to maintain an upright stance and shifting the mast foot forwards actually stops you leaning forwards to get weight over the rig when wave riding down the line.
On a slalom board or on freeride kit you are generally using a single fin and the bigger the sail the longer that fin will be. The mast foot position then controls two things, 1) the distance of mast to fin – and that in turn controls how much lift you get from the fin. 2) The mast foot position also determines your stance when blasting along, and shifting the deckplate forwards angles the mast back, effectively dropping the boom, and thus setting the sailor weight more on the tail. So with blasting and slalom kit you might shift the mast foot forwards for more control and backwards for more speed.
With most boards, my recommendation is to just stick the deckplate in the middle of the track, and then leave it there. That ‘constant’ then helps you establish good stance by removing one variable from your board set up.
huge amount of variables.
board type and rocker
fin type
sail center of effort
sail shape
wind and water conditions
one could write a book about this.
base back, more lift from fin. base forward, more lift from rails. too far forward, spin outs and bow wake sprays to the face.
too far back, crappy low end planing power, possible out of control wheelies.
trial and error for years to figure out what’s best for individual.