"tony thomas" wrote in message
news:FFKxd.535630$wV.355519@attbi_s54...
While true that props can be built to have tail/stern lift and/or bow
lift. This does not come into play at lower rpms that your talking about
to maintain plane. Higher rpms are required to have any effect. So prop
lift will have no effect.

As stated before - planing speed of a hull is planing speed. No prop is
going to change that.

Like I said, I think that many boaters misspeak when they're discussing
planing speed. When they say "my boat planes at 20mph", they mean that that
is the minimum speed they need to run in order to *stay* on plane. However,
it's quite possible that his boat planes at 17 mph, but won't maintain that
speed...and thus he interprets that to mean that 20 mph is his minimum
planing speed.

A lower pitched prop may allow such a boat to *maintain* a lower constant
planing speed.