Prop spins when in gear

[Nickm9921]

The prop on my Oyster 39 spins when sailing. On my previous boat I always locked in prop in reverse (controversial) but when I try this with the new boat it still spins freely. Is there an issue with the gearbox?

 

[Malish]

Depends on the design of the gearbox - is it hydraulic?

 

[ghostlymoron]

I've seen some research which concludes that the drag is significantly less if allowed to spin. The whining noise is annoying though, especially if you're trying to sleep in the aft cabin.

 

[Pete7]

I've seen some research which concludes that the drag is significantly less if allowed to spin. The whining noise is annoying though, especially if you're trying to sleep in the aft cabin.☹

Indeed: Sailboat propeller drag - Strathprints

 

[NormanS]

Having a Bruntons Autoprop, I have to lock it when sailing, so that it behaves. I engage astern immediately before stopping the engine.

 

[Supertramp]

Does it spin in reverse when you engage reverse with the engine running? My understanding and experience is that engaging reverse with the engine off stops the shaft totally.

I always leave mine spinning in neutral when sailing, which it does from pleasingly low speed.

 

[srm]

Have you tried putting the gear ahead with the engine stopped while sailing. Think I read somewhere on here a gearbox control had been set up incorrectly so ahead stopped the prop.
However, if it is a hydraulic box my understanding is that they should not be allowed to freewheel and you need a shaft brake.

 

[doraymefa]

What prop do you have? If fixed prop and hydraulic gearbox then you will not be able to stop the rotation. If allowed to spin under sail for long periods I understand that it is a good idea to start the engine and put the engine in gear to allow oil to circulate at intervals.