We sell many different windsurfing mast extensions. There are two types of windsurfing extensions, SDM Standard Diameter Mast extensions and RDM Reduced Diameter mast extensions. Shortly MDM with be arriving in stock here at Boardworx in the United Kingdom. This new size was developed by North windsurfing and is a size between these sizes.
The SDM windsurfing mast extension is designed for a fatter mast size of 48.8mm and is what most older windsurfing sails are made for, and also sails larger than 6.5m. RDM was developed for smaller windsurfing sails, and the internal diameter of these masts is 32-33mm. The new MDM has been designed for the windsurfer who wants the light weight of an RDM but wants the power given by an SDM mast.
Most Windsurfing mast extensions are adjustable in length so you can use them on different size sails. You can have fixed-length mast extensions, but these are rare. The sailboard mast extension is essential so you can rig the sail correctly.
The Windsurf extension is made of Carbon or aluminium, and carbon extensions are great to use as they are so light but costly.
Here at Boardworx, we think the Duotone XT mast extension is the best on the market. It has a simple ratchet system for downloading the sail to precisely the right amount of tension.
Some of the strongest wave and slalom windsurfing extensions are made by Chinook, known for making solid windsurfing accessories.