Hull/stringer build quality of mid 80's formulas
 

Hello, posted another thread about buying and options. but on this one wanted to ask a question pertaining to the hull quality.

Noticed in looking at the old online Formula brochures, that in at least 85 and later formulas they mention the use of structural foam. What is the opinion on this?

I notice in the Scarab forums, how many threads deal with stringer rot and transom rot. Does the foam help prevent that at all or just in front of the bulkhead ahead of the engine bay?

Are formulas just a prone to the rot as Scarabs and Baja's seem to be, or is there a better chance of them being sealed up better and does the foam add anything?

How do they check for rotted wood or hull moisture in a survey? Drill a small hole and insert a probe or pull a sample?

Thanks, great forum guys and gals.