Not my boat

[Nevs]

Someone I do not know is making his first boat on a very low budget. (and makes his first mistake ?)...

http://www.rcgalleri.dk/fotoalbum/teknik-projekter/36485-projekt_metamarine_tnt_46_corse_rc_baad

Hull 3650 g...The strut he bought is with 3,2mm flex..
I surgested 15-20.000 rpm and a 50 mm prop and about 30 mph..But I do not really know how a 3,2mm flex will work in an almost 8 pound,(emty) boat. The 2 times I ever used that size was in small 2-3 pounders.
Anyone who has any experience "with the combination" ?

[Speed3]

That shalf is too small, 3/16 size
for a shalt would be better considering using a 50mm prop.