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otnmbrd
 
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Default Which way does a boat turn?

Comments interspersed:

Rod McInnis wrote:
"JAXAshby" wrote in message
...



Q: same question, rudder centered, but tranny in reverse (bow of boat tied


to

dock)?

A: the stern will move to port due to prop walk




I would have said to starboard, reason being that I would expect it to be
the opposite of the prop walk direction when in forward gear.


I believe he was talking about a RH, fixed pitch prop, no wind or
current.....stern should go to port in reverse, to stbd when ahead.

I have heard several different theories for "prop walk".


G Same here .... My opinion FWIW, prop walk is a function of the prop
and pitch. The angle of the shaft may increase it, but is not the basic
cause as will some hull shapes and prop locations (tunnels or nozzles),
increase or decrease it.....




There can be other reasons why a given boat kicks one way or the other.
Some inboards I have seen have the rudder mounted just off center, which
allows removal of the prop shaft without having to remove the rudder (which
it would hit if the rudder was on center). I would expect an off center
rudder to have some effect on prop walk.


My first impression is that this would have minimal effect if any, G
would need some test, and although I've worked some boats with various
rudders types and locations, I can't say that I've ever noticed a
difference that I could attribute to the rudder.


What is the dominant effect? I have no clue. I don't care. I do know that
my single engine inboard is impossible to steer reliably in reverse. It
usually (but not always) kicks to port in reverse.


Going to assume that you have a RH fixed pitch prop. This is the norm,
however, wind and/or current can make a boat which normally backs to
port because of the prop, back to stbd from the "get go".
Steering your boat "reliably" in reverse, would involve many possible
solutions, including "your boat just won't steer reliably in reverse".

Which is why when you see
me going down a tight fairway in the marina I will be hugging the left side
as I can turn right much better than I can turn left.


Interesting. Normally a single screw RH fixed pitch prop will steer more
easily to port than to stbd, unless you are talking a back and fill
turn, in which case you want to turn to stbd.

otn