53MY props

It depends on a few variables. New specs don't account for our typically well owned vessels full of our cruising gear, extra tanks, not quite pristine bottom paint, etc. The first thing to check is if the engines turn rated r.p.m. at w.o.t. with the boat as you usually operate it. I would check this with the current props before you haul out for paint. It is also entirely possible that your 28x29 props have had their pitch tweaked at some point in the past and aren't 29 in. pitch anymore. You could have them checked by a prop shop (not a bad idea anyway) while you are on the hard. If you have the 28x31's installed and aren't satisfied with how the boat runs with them, it is relatively cheap and easy to have a diver swap them back to the 29's later. If they don't allow full engine r.p.m. though, you will likely see a decrease in performance.

 

Hi Mike. Assuming Hatteras originally specified the larger 31" pitch, you should see a higher top end and possibly achieve hull (displacement) speed at a lower RPM. A factor that should be considered is how much gear (weight) you and or the PO have added over the years, as this may be the reason she has 29" pitch wheels instead of the oem recommended 31".The objective is to turn as large a propeller as possible while still reaching maximum governed RPM, which I believe is 2350 for 8-71 TI's.
Best of luck!
Rick.