400rdm

What sort of sizing is small medium large and xl. what happened to 4.2, 5.0 etc. That really messes with my head. But good to know...i think. Thanks caipi

they are big sails fibersnap. i'm more bump and jump style. the big sails scare me., iv'e been bitch slapped a few too many times. maybe it's the board i ride. perhaps i should do more light wind sailing on the F2 ride 279 i have been given.

I can get away with one RDM mast and an 30cm North silver extendo.(30cm length of carbon that extends mast and can still have extension inserted).
sails 3.7 to 5.2 , all rig fine with Sevene Gorilla wave mast and 30cm carbon extendo. 20cm extension needed on top of this for 5.2.
One mast solution

It is possible but with a 4m mast you will lose some high end. A too stiff mast make your sail more nervous and twist less. a too soft one make your sail twist too early and losing the low end punch.
I would opt for a 2 mast combo or at least buy a mast where you can use a 400m with a single 370 top-part.I,m sailing with Hotsails.
I can rig my 6.0 till a Superfreak3.7 on a 370 mast (I prever the 370 in that sail over the adviced 340 that I have as well).