I took my 28' S2 out with the new 2 bladed plastic Perfect Pitch prop
from Performance Props. My engine is the Yanmar 2gm13. At half
throttle, I got 5 kts (new bottom paint too). At full throttle, I got
6.5 kts. This seems ok. Am trying to find the log of a cruise a
couple years ago with the old three bladed bronze prop to compare
performance. I cannot yet ascertain anything about performance in
reverse although this was never an issue for me.