NicoDC said..
... but many of you seem to be on carbon masts. They are much more expensive and fragile ...
My experience has been the reverse. From the early days of kite foiling huge amounts of maintenance and repairs to aluminium masts. Zero maintenance and repairs to carbon masts.
My kite and wing foils have had their fair share of grinding into the bottom and the occasional bump into rocks. The only damage has been chips and scratches to the foil tips.
The kite foils are jumped frequently with all sorts of unco landings. Zero damage over 1000 hours of use.
The cost per hour of use of my kite foil gear is tiny. Maybe $5 an hour. Wingfoiling gear has been much more expensive but the gear arms race seems to have tapered off so that should change.