Catalina 310 propeller sizes

Jan 17, 2013
439
Catalina 310 St. Simons Island, GA
I currently have a 13 x 9 three blade fixed prop and am wondering if a move to a 15" prop will gain more speed. Engine is yanmar 2GM20F, 2 cylinder, 18 hp and I would really like to gain more boat speed under power. Currently get 5.0-5.3 knots at 3,000 RPM with no wind or current (which never happens) and would like to get close to 6 knots. Not sure what size prop most Catalina 310's are using?
 
Feb 21, 2013
4,638
Hunter 46 Point Richmond, CA
Hull speed for a Catalina 310 is 6.9 knots. A larger diameter and pitch propeller will offer higher top end speed at the expense of lower acceleration or thrust. Catalina sells a 3 blade fixed 15 x 9 and 15 x 10 propeller for your boat (links below). Whoever you purchase the propeller from be sure the propeller manufacturer/supplier confirms your motor hp and transmission gear ratio will support that propeller.


Selecting the correct propeller size: How to choose the right propeller for your boat - Practical Boat Owner
 

JAE

.
Feb 15, 2021
21
Catalina 31 38 GIG HARBOR
I currently have a 13 x 9 three blade fixed prop and am wondering if a move to a 15" prop will gain more speed. Engine is yanmar 2GM20F, 2 cylinder, 18 hp and I would really like to gain more boat speed under power. Currently get 5.0-5.3 knots at 3,000 RPM with no wind or current (which never happens) and would like to get close to 6 knots. Not sure what size prop most Catalina 310's are using?
We have a 3 blade max prop (expensive yes, came with the boat) it EASILY pushes us @ 6+ knots and reversed like magic...I recommend if your budget allows.
cheers
 

leo310

.
Dec 15, 2006
635
Catalina 310 44 Campbell River BC
I run at 2000-2200 5-6 kts as it just to get out of the harbor. Most of the time its around .5-.75 lt/hr.
 

JRT

.
Feb 14, 2017
2,037
Catalina 310 211 Lake Guntersville, AL
@Cat 310 #1 in GA isn't your motor the smallest in any 310 because you have hull #1? @leo310 said he has a 29hp which would make a difference. Unless you plan to repower I'd call some prop manufacturer and get their input.
 
Jan 17, 2013
439
Catalina 310 St. Simons Island, GA
@Cat 310 #1 in GA isn't your motor the smallest in any 310 because you have hull #1? @leo310 said he has a 29hp which would make a difference. Unless you plan to repower I'd call some prop manufacturer and get their input.
You are correct so comparisons with other 310 owners are not necessarily applicable. Wanted to ensure that the 310 can accommodate a 15" prop which it obviously can. TBD whether that makes sense for my current engine so I will be discussing with some prop experts as you suggest.
 
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rukidn

.
Apr 23, 2012
160
Catalina 310 258 Sandusky, OH
You may want to also note your speed at idle before consulting with prop manufacturers. The broker put a new 3-blade 13" Sailor prop on our boat just before we purchased. (I don't recall pitch). We could not get over 2600-2700 RPM, but idled at breakneck speed. I had the prop de-pitched when we moved the boat from TX, but still wasn't enough. Wide open is ~2900RPM and we idle at over 3knots. We do sip fuel at 2000RPM, in the high 5knot range. In and out of gear in the marina will age the transmission of course. It's down on our list of fix/upgrades, but I wanted to point out that idle is also an important consideration.
 
Sep 6, 2018
20
catalina 310 285 waikawa NZ
hi there, have a look at the kiwi prop , adjustable pitch, folding, excellent reverse, composite construction. do not expect too much from 18 hp.