You are down 5 mph at top end?

Where do you spend most of your time cruising at 3000-3500 rpm or WOT? Top end is nice for brief moments but I would rather cruise in comfort at lower (quieter) rpm. Saves gas too. That said I went from a 21p to 19p for most uses. I'm going to take an all day cruise later this month and will put the 21 on for a little better economy.

That change only affected my top end about 2 mph though

Do you believe that one has to lose 5 mph and weaken your hole shot to get mid range?

There is compromise in everything. 5 mph is a lot I think. So I guess the answer is yes seabuddy, any change you make to a prop that affects low end will most likely affect top and mid range as well. At least until they come up with variable pitch for boats.

Swap some mph at top end for a better hole shot, ok IMB.

Mid range cruising is not really tied to one or the other, often, to me. It can go either way, depends on alot of stuff.

BTW, it's my understanding that an Offshore design is about the worst prop choice for mid range in an I/O that I know of, even if it was a new prop, not a used one.

If with prop A it takes 3000 rpm to cruise at 30 mph and with prop B it takes 3500 rpm to cruise at 30 mph that is a mid range change. I think with my prop change it was more like 3000/3250 but it did have an affect. I did notice better hole shot but not much else power wise. I can attribute the 2 mph WOT to any number of conditions, temp humidity, current. I have actually hit top speed of 55 with both props but I think with the taller one in cool temps, I may hit 56 or 57. Not a big deal. But I do notice gas consumption difference, at least I think I do.

That does not sound like a Offshore prop, what did you use for your change?

In Tim's case he went from a 17p to a 19p and in Andy's case from a 21p to a 19p so we need to isolate prop design from simple pitch changes, correct?

It is interesting and surprising that Tim's Solas that was 2" higher in pitch 1) produced the same max rpm and 2) lost top speed. To me that indicates a pretty severe difference in design.

Andy, did you go from 21p to 19p with the same model prop? What model prop or props are you using? Thanks.

EDIT: Tim's higher pitch prop holding plane better (at lower speeds) surprises me also, at least on a pure pitch change basis, but maybe it shouldn't?

To my experience, yes.

athiker: It's not that it is holding plane at lower speeds, but it is turning fewer RPMs in order to do so. I didn't notice much of a difference in the minimum planing speed, it's still somewhere in the 17MPH range with the new prop.

I believe (but cannot confirm) that the blades on the Solas (19P) are smaller than the ones on the Offshore (17P). I'm not a fluid dynamics expert by any means, but I would think that the difference in blade design and size could negate any gains that you might think would come from the 2" pitch change.