Noise / Vibration while turning under power

[R Martin]

While turning under motor power there is a definite vibrating noise coming from under the aft end of the boat. (i.e. prop, rudder or cuttless bearing?)  I have had this problem since I purchased the boat almost a year ago.  At first, the dealer said it was normal for Catalina 34's but as I have persisted that it is not right they are starting to investigate.  Does anyone else have this problem?

This is a new Catalina 34 MKII 2001.

[amoreau]

Hi,,,I have the same problem but I always thought it was just cavitation during the turn under power.  I have a three bladed prop so it might even be worse than a two bladed.

[Ron Hill]

Give us some hints.  It happens at all RPMs??  In both fwd and reverse??  Any other symptoms?? It's always there and never goes away??  It's even there when the engine is off, but the prop is freewheeling?? ETC ??  Ronphylhill@erols.com   ;)

Ron, Apache #788

[Roc]

I have hull #1477 (2000 model) and mine does the same thing.  Soon after I bought the boat, I called Catalina and spoke to Gerry Douglas about it and he said it's normal.  It's cavitation as the stern is pushed hard to one side.  This usually happens when moving forward, in gear, with the rudder hard to port or SB.  Plus, the boat needs to be moving at quite a good pace.  In reality, how often is that the case, that's why I don't worry about it.  I also have a 3 blade fixed prop.  
Roc-

[R Martin]

The noise is at all RPM's while making a turn in forward. Although it is much louder at faster speeds. I have never noticed it in reverse.  However, I did notice it one day while offshore with 3-5 foot seas on the starboard beam with the prop freewheeling.  The boat was being pushed laterally at times.

This is a 3 bladed prop.

Thanks for all the input.  This is a great web site and one reason I purchased the Catalina 34.