Reversing problem with folding prop - Propwash?

[Guest]

Have got a 25ft sailing cruiser (Caravela 25) which will only steer in one direction when reversing. Turns in a clockwise arc (to port) fine, but just reverses in a straight line if I try and turn to starboard (even with tiller hard over).

I've heard that this is called 'propwash', and its not uncommon.... but could it be particularly bad because I've got a folding prop fitted (Autoprop)?

Would appreciate any advice... thanks.

 

[Guest]

not an answer, just a question

As I am fitting an autoprop I am interested. Does it still behave as described when the revs are dropped? With my old fixed prop I only ever managed to steer in reverse under no or very low revs so I gave it quick bursts.

 

[Guest]

A possible answer

I've an Autoprop and experience very little prop walk either astern or ahead. Basically at slow speeds the blades adopt a very fine pitch, hence you need more revs to get moving, once under way the blades present a corser pitch and you can reduce revs. The fine pitch reduces prop walk.

If you are fitting it to a saildrive make sure you fit a hull anode as the extra Bronze lump on the end quicky disposes of the saildrive Anode.

 

[Guest]

Thanks for the ideas

Think I've generally been using low revs - reversing carefully into a berth etc., but it may be that I've been giving it a burst to cancel out movement ahead. I'll try quick bursts/low revs and generally experiment. Thanks to both of you for the info.

 

[Guest]

More ideas ...

... every boat seems to be different. I reverse into my marina and my boat (fin keel, blade rudder - not much directional stability) walks off course despite helm until I have some way on. I get up a bit of speed with helm midships to minimise walk (lateral resistance) and then go into neutral and steerage is then good. Experiment with revs - the "walk" can actually be very useful in certain circ's.