Surf and sail Australia have them for $29.95.
www.surfsailaustralia.com.au/product/chinook-tendon-joint#surf-sail-clothing-hardware
That link should take you there.
Cheers. But I need the whole thing. The kit I brought is missing it.
Most suppliers don't seem to have it in stock. I have the base plate and mast extension but need the joint
I would think every windsurfing shop in the country has mast bases. You know it does not have to be chinook brand?
If you can't find the type of base in that pic, you can use the single bolt spin-on style without your two-bolt deckplate.
Like this:
They grow on trees.....
You can buy them from the Chinook importer in Perth, last time u got some they were $20, my chinook base had to have there tendons as the pin size was a bit bigger.