Hi
What exactly are you looking for --- an adjuatable pitch prop. or a
variable pitch prop, going forth and reverse as in old fishing boats ?

Both cases you are to put down quite a sum, the adjust pitch are rare
and expensive the fishing boat types are usealy only two blades and
only few manufactores make these and only to fit onto their own motors
, if 3 blades they cost more than 3 gearboxes all together and you
still need the piece to do the pitch move. ------ what is an e-boat ?