View Single Post
  #15   Report Post  
Larry
 
Posts: n/a
Default Jet Boat Autopilot

On Mon, 1 Dec 2003 17:26:34 +1030, BruceM wrote:

Like Michael said Larry,........... Every boat & every sea (following, head,
etc) has it's own particular set of behavioral problems or idiosynchrosies.
I think as long as you don't expect it to be a really sucessful setup, then
you won't be disappointed.
I had a chat today with a pro fisherman & he said that if you set it too
"tight", all your equipment in the steering department would be "overworked"
trying to keep you on course that it wouldn't last long.
Much of his work is in seas with a diagonal swell on his way out & back from
the grounds. His auto-pilot is set with a wide path so that the boats
natural veering behaviour on the up side is allowed to "happen" without
correcting so that the natural opposite veering in the other direction on
the down side is back to within the course allowed. Hope I'm making sense.
If the pilot has to "fight" it one way, it then has to also "fight" it the
other.
That is with a boat that has a decent skeg & a big rudder. Probably similar
to a yacht with a decent keel. Imagine a yacht without a keel?
All in all, with a jet, don't expect too much.
"Michael Ohlhorst" wrote in message
...
Hi Larry,


I recall from years ago that handling large craft was very much the same
thing: you applied rudder and the reaction was delayed. Stopping was
similar - you approached slowly and with caution and reversed engines

well
before you wanted to stop. All of this is what I generically call
"damping" - anticipation of the effect and a delayed reaction to change.
Now my experience with autopilots is practically nil - the only time I

used
one was very brief and basically it just kept the boat on course. I had
hoped that when you set up an autopilot, that you could trim the amount

of
steerage. Are you saying that you can't?

As i am going most often alone with my Boat i have to use the autopilot

for
a lot
of times when i am busy.
The worst situation was a trip at the german north sea between Cuxhafen at
the Elbe and
Helgoland the distance is around 70 miles open water. The weather has

turned
from bad to
impossible and as my flybridge was not ready to use i had to steer form
inside. The lithouse of
Helgoland was in sight but i was not able to steer a usefull course. The
waves are so strong that
my dutch 52feet Motorboot was doing 90 degree course changes within 5
seconds. The only way for me was
using my robertson AP3000 sitting on the sofa and hoping the best -which
lasts 5 hours as the boat is doing around
8 knots in good conditions.

The trimming of an autopilot is the most horrible thing to do. When it is
funktioning in calm conditions it is not working
in rough sea and when its working there your boat is moving like a drunken
sailor at a mirror sea.

Michael




Thanks to all,

I've done a bit more research in addition to what I've read here and
pretty much decided to scrap the idea. Bombardier is just about useless -
virtually no technical help at all. When I asked them about adding an
autopilot, they said they would not help and would pull the warranty if I
did. I already had a brand new engine blow, and the deaIer had to fight
with them to replace the engine with a new one. I think I'll no doubt sell
it next season while the new engine is still working. First and last
experience with Bombardier. I added trim tabs, and they have helped it a
bit, but after visiting the Hinckley site, I am remembering what real boats
are like....

For now, I guess I'll just use my knee to hold the wheel while I eat my
sandwich! I'll start a new thread about the new boat in a different
boating group.
--

Larry
email is rapp at lmr dot com