Thanks David,
my information on the "feel at the wheel" came from a Raymarine rep. and
Simrad documentation. I have no first hand knowledge, but suspect it is a
fairly minor difference. The mechanical drive may use just as much juice,
but I have convinced myself that it less. I was less concerned about the
durability thinking that if I were doing heavy duty use of an autopilot,
that it would be with a Monitor windvane and not the electrical anyway. I
have also heard that the Raymarine "may" have better wind algorithms and I
am experienced with their wheel pilot and very comfortable with the user
interface. I ordered the Raymarine today.

"David&Joan" wrote in message
newsRkJd.438$Jt.39@fed1read02...
John:

I have used both a Raymarine ST6000 with a rotary electric drive and a
Simrad/Robertson AP11 with a hydraulic drive. There was no significant
difference in power consumption. The hydraulic drive (with an integral
pump)
only runs the pump when it needs to. If I watch the ammeter, I see about
1-2
amps normally and it jumps up to 3-5 amps when the pump kicks in. The
linear
electric drive does about the same.

In general, hyraulic pumps and cylinders are pretty robust and probably
are
less prone to failure. As others have said, with the hydraulic system
disengaged, there is very little drag on your steering. Mounting a self
contained hydraulic actuator is no different than a linear electric
actuator.

The Raymarine has a better user interface and I think, a better algorithm
for dealing with various sea states and imbalanced helm conditions.

So my vote would be Raymarine electronics with a hydraulic actuator.

David