One problem w/ bamboo is its breaking point isn't so high as one would believe, unless you pick large diameter, not so economical stringers.
Another problem is its diameter changes from one end to another, and those ends ain't perfectly round, which makes assembly difficult.
It's not imposible to use, but far from a first choice.
PVC lacks resilience or would be too heavy.
Carbon fiber can do he job, but my 1st choices would be aluminium (choosing the wall thickness according to the desired use, for sea expeditions 1.5mm is safer than the regular Feathercraft 1.2mm) or wood (ash the stronger choice for seafaring, or pine, fir, spruce, beech).
Depends on the lenght of the yak, too.

: I was down at the local hardware store and noticed that they have quite a
: selection of bamboo stakes from 1/4" up to 3/4" and 10' long.
: There was discussion recently on bamboo for use as strip material but how
: about for SOF?

: grant