They don't say good performance without a good mast. A good windsurf mast is an important part of your windsurf setup. That is why it is important that you choose the right mast for the sail you want to sail. You can imagine that a wave mast has a different characteristic than a mast that you put in a racing sail.
The function of a windsurf mast
A wind surfing mast ensures the profile of your windsurf sail. During windsurfing the mast moves mainly sideways in relation to your board. Together with the shape of the sail, the profile of the sail becomes visible. The degree of tightening of the bottom provides a flatter or bolder profile of the sail. The mast bend determines where less and more profile is built up in the sail and where the sail releases the wind during gusts. The sail designers take this into account during the design process, so it is important that you follow the manufacturer's advice and put the right windsurf mast in the sail.
Standard Diameter (SDM) or Reduced Diameter (RDM) windsurf mast
A standard mast as we know it has a diameter of 48 mm. The bottom is wider than the top. The mast was therefore tapered. You increasingly see the RDM masts on the water. These masts with a diameter of 33 mm are not only thinner but also more robust. This is because you can use a larger wall thickness with the same weight. This makes them stronger than standard masts. This allows you to see that the skinny mast is used a lot in wave and freestyle sailing. With a skinny mast (RDM) you need a different boom and extender.
Hardtop, constant curve and flex top windsurf masts
Three different types of masts are available. Each has its own specific characteristic.
With a hardtop, the top of the mast is stiffer than the bottom. Hardtops are mainly used with GA-Sails. From 2017 it will become a Constant Curve at GA-Sails
Constant curve masts ensure a gradual bending of the mast over the entire length. North Sails and Severne use this flex in their sails.
Here the top is smoother than the base of the mast. Neil Pryde uses this flex in their sails.
The windsurf towers have a difference in stiffness per length. This is indicated by IMCS (International Mast Check System). A longer mast is stiffer because it has to hold the profile of the sail over a greater length. Most masts have the following ICMS values:
340 cm - 13 IMCS
370 cm - 16 IMCS
400 cm - 19 IMCS
430 cm - 21 IMCS
460 cm - 25 IMCS
490 cm - 29 IMCS
520 cm - 32 IMCS
550 cm - 35 IMCS
Carbon stands for light. So the higher the carbon percentage of your mast, the lighter and more responsive your sail will feel. You notice this while sailing. The gusts of wind are converted into speed, your sail sails more stable, more direct and not unimportantly, lighter.
Use of carbon in percentage
15% carbon - beginners sail (or low budget surfers)
30% carbon - Wave, Freestyle, freemove and freeride use masts from 30% carbon
75% carbon - Freerace, racing, speed and slalom sailing use windsurf masts of at least 75% carbon.