Catalina 27 with 5411 & 2:1 trans. How fast?

[John]

My boat has a three bladed prop (I've also tried a two bladed) and under normal conditions I can do about 4.5 to 5 knots. My bottom is cleaned every month the engine runs great and I sail almost evey weekend. I heard several people claim they can get their 27' with the same setup up to 6 & 7 knots easily. Is there anyone else out there that can also get that speed and has it been checked by a GPS? If so is there anything special you have done? Or do you have any ideas why I can never get up 5.5 to six knots, trans, prop, etc? Current where I sail is not that bad. I understand that there are a lot of variables involved here but some basic answers or ideas would be great. Or maybe these other boats are full of shi__? Lots of tall stories at the docks! JOHN

 

[Roger]

I don't do hull speed under power either

I also have a three blade prop and 5411 on C27 #5012 (1982). While I do not have a speedo, and GPS speed over ground is highly influenced by our currents and choppy seas here,I believe that under power I cannot get to the theoretical hull speed of 6.2 knots. Maybe a little more than five in still conditions. Once heading into six foot seas head on I alternated betwen 1 knot and 3.5 knots as we plowed into thenwind under power. On the other hand, in good breeze on a broad reach I have seen pretty high numbers (over 7), and once in the Cape Cod Canal it was over 9 knots! ('course the current was with us and was really zipping).So my experience is more like yours. Maybe somebody out there can give us both a hint or two.Roger

 

[Warren]

Motor speed

I have an outboard Honda 8hp 4stroke and under calm conditions I will see between 5.9 and 6.1 kts gps speed obviously there are no currents in the lake I do drop off to about 5.1 in a 12 -15 kt headwind. We have a 1972 c27 model which I believe is considerably lighter than the later models, maybe that would contribute to the speed diference.