Type prop for Catalina 30 with Atomic 4

[rjkerby]

Can I get a few opinions on the best prop for a Catalina 30 Mark 1 with an Atomic 4.
The boat is raced and cruised and it doesn't have much power in reverse. Cruises at 6 Knots @1800 in calm seas,with an 11x7 2 blade but I'd hate to have to make an emergency stop.
Thanks

[JOHN COOKSON]

Maybe you need a trany adjustment? Because reverse is not fully engaging and slipping a bit?
Disconnect the shift cable and try shifting by hand with the lever and see if you notice any difference in lever travel or performance. Or maybe the trany itself needs to be adjusted?
I'm going to go out on a limb and say a 12X8 sounds more suitable for a 30 footer. Wait till the Cat 30 folks come along for the final word.

TRUE GRIT

Edit: Welcome to the forum. Tell us a bit more about yourself. How long have you owned an A4? Anything you can tell us about the engine? This is a safe place. We learn by sharing.

[Mo]

Just a couple of things:
-sounds like you have the right prop, or at least very close. John mentioned 12/8, anywhere in that ballpark depending on conditions you work it in.
-are you holding handle up in reverse and allowing it to engage? We have to continue to hold the handle in reverse, not the same as forward.
-Not the same as stopping a powerboat and not the same thrust as in forward: I hold my boat at 2 kts coming into the marina; once about 100 feet from my spot I reduce speed and want to be doing 1.5 kts when I make the turn to park at my dock. At this point I am 40 feet from where my bow will sit and the engine is idled down. When lined up I put it in reverse 20 feet back and hold in reverse. The boat will slow more and you can give it a shot of fuel for the final thrust to stop. It is very hard to stop a sailboat if we come in at 4 kts, pull the handle and throttle up...takes time and room.
-reversing gear adjustment: ensure the linkage from the cable is attached firmly to the piece on angle iron on the reversing gear. If that is loose it can cause issues.
-there should be about 2-3 second delay from when you hold that handle in reverse firmly until you hear it engage. You will hear
a winding of gears then a different sound as it engages.

[JOHN COOKSON]

I presumed you have a 12X7 fixed blade - not a folding prop?

TRUE GRIT

[rjkerby]

Hi John, it's an 11-7?? (11" for sure) two blade fixed. I've replaced the 1/4" shift cable with a 5/16" cable. The reverse goes in and make a lot of noise and has wash at the front of the boat dockside. I've just rebuilt my A4. the prop is my spare and I'm going to buy another or get my old 12-7 rebuilt.
I know the Cat 30 is not a race boat but I enjoy the PHRF racing in the Puget Sound. My wife feels she would be a lot more comfortable if we could stop in an emergency.
I've had this boat since 2009, 1975 Catalina 30 Std. #103. I've replaced all the rigging , rebuilt the compression post and bilge, fixed the smile and we really enjoy the boat and Sound sailing. During the spring we race as often as I can and summer and fall we cruise the beautiful area we call home

[Dave Neptune]

rj, consider the Indigo. The prop works well and as it is not very big it compares with the two blades for drag however you will get a 3 BLADE RATING which is an advantage. This has worked nicely for me.

Dave Neptune