I much prefer the 90cm mast.
More relaxing sailing as breaching is much less common when foiling around the foil max speed of 18 to 21 knots - more time to control ride height with foot pressure.
Also the taller mast means you touch the nose down less often going upwind in ocean swells.

The foil seems equally maneuverable riding swells downwind with either mast.

I think the 70 cm is good for the first few sessions as beginner crashes from the lower height are easier to recover from.
The only other advantages I can think of for the 70cm mast are obvious - not needing as much depth of water and easier to beach start.

Love the Naish WS1 for freeriding, downwinding & small waveriding

bensen said..
Thanks Azymuth: I have the NP alu, the Bic (ker), Horue carbon, Naish Thrust ws1 70 and the F4.Think the Naish is best in lowend conditions.I might order a 90 cm mast then.

www.bensens.dk

Hi Bensen, how easy is the horue to use compared to the Naish? Does the Horue get going in less wind/small sails than the NP alu?