GPS Off Course setting? LI. Great south bay.

[JohnEGraham]

Hi, I have been setting up my new GPSMAP 440S Routes What is a good starting point for the " OFF COURSE " alarm,
I do my boating on the Great South Bay which can be very tight with many Sand bars. I was think of 100 ft. to start. Thanks. John G.

 

[Lazy Daze]

100 feet is cutting it pretty tight. Depending on your experience level (I'm not judging), it can be hard to maintain that course accurately enough when you take into account wave/wind action and keeping in mind that GPS is still not dead-on. That's only about 4 boat lengths in one direction. But, I'm not saying it can't be done and if where you are going to be going is as tight as you say, then that sounds like a reasonable starting position. You'll just need to stay on top of it - which I guess is what one is supposed to be doing, anway. :wink:

 

[JohnEGraham]

Ok, Thanks. Just looking for some kind of starting point, I will start with 200 ft. since the boat tends to drive a bit loose with the deep hull & single stren drive. JG.

 

[bmac]

I have mine set to 10 ft.....only joking, but mildly so. The GSB is generally ok east of the RM Bridge but west of there, in the State Channel, on the South side of the bay by Kismet and east of Patchogue can be tough places to boat with fairly narrow and shallow channels. Don't even ask about Moriches Bay....I'd keep a close eye on my depth sounder and depths on the chartplotter.

Hi, I have been setting up my new GPSMAP 440S Routes What is a good starting point for the " OFF COURSE " alarm,
I do my boating on the Great South Bay which can be very tight with many Sand bars. I was think of 100 ft. to start. Thanks. John G.

 

[Lazy Daze]

Ok, Thanks. Just looking for some kind of starting point, I will start with 200 ft. since the boat tends to drive a bit loose with the deep hull & single stren drive. JG.

You might very well be OK at 100. Try it. You can always change it.

When you say "loose", at what speeds are you talking about? Below 1,000rpm?

 

[JohnEGraham]

The more I think about it being a "new" boater. I will make changes depending on which way I head. I am in lindenhurst so, If I head east and keeep to the north Chanel I will use 150 to 200ft west I will use 100 if I head east or west and use the state channel I will use 25- 50 ft. Thanks all. John G.

 

[sbw1]

My gps cross track error is set at 61 feet or .01 NM. The auto pilot holds that in just about all sea conditions on Lake Michigan where the leg of a trip is often over 100 miles before a heading change. I can hold a heading without the pilot to within .01 NM unless my mind starts to wander from talking on the radio, moving from screen to screen on the radar or chart or when the sea is rough. Then the alarm goes off fairly often.

 

[JohnEGraham]

Loose< Yes, I go back and fourth at slow speeds. Like my golf game. What we called military golf. Left,right,left,right..... John G

 

[Lazy Daze]

Loose< Yes, I go back and fourth at slow speeds. Like my golf game. What we called military golf. Left,right,left,right..... John G

Very normal. It's called "wandering". Partly due to "prop walk" - as it spins, it tries to also move to the side. The B3 eliminates a lot, if not all, of that. The other cause is the hydrodynamic effect of the water along the side/stern corners. It actually pulls the boat to one side, then the "tension" there breaks and the other side takes over. I'm not doing the explanation justice here, but hopefully you get the jist.

In time, as you get used to your boat, you'll be able to sit there with a drink in one hand, talking to guests, while at the same time constantly be correcting for this with the wheel - sort of countering the effect before it happens. It'll become second nature.

Try different "slow" speeds, as well. Just a little bit faster may make a big difference. I've heard some people say that lowering trim tabs and/or changing the angle of the drive can help. On my hull, I've never noticed enough of a difference to make it worth while.

 

[JohnEGraham]

Lazy Daze..... Yes, I also had a lot of repaires done at the end last season. Before the repaires, I would have to move the steering wheel nearly 1/2 a turn to get any movement of the outdrive. So part of my memory was before the repairs. If I wanted to move the boat to the oppsite way I would have to move the wheel a whole lot just to start the outdrive unt.
Now I move the Wheel only a few inches a the drive responds (what a concept)
I forget what was fixed but while the engine was out the bottom part of the lower unit had to be removed ( nice new Caulking on the outside of the boat ) and the Steering wheel cable ws replaced.
Thanks John G.

 

[FireIsland1]

The north channel on the chart is not where the bouys are. This is from lindenhurst to the bridge. You might try doing a run and hit waypoint button while in the marked channel.

 

[JohnEGraham]

FireIsland1..... Ok, I think I got it.
I only see " North Cannel" marked only once on my Cart Page 23. which is right below a the Red solid line shows: ""see note G" I assume this is a safe way to head east once you past the Bridge
Now... Once I turn east from my marina in lindenhurst I follow 3 sets of bouys with the last set ending at the " Oak Island channel" than head to the middle of the Robert Moses Causway and Pick up the ( see Note G ) Route. The only problem I could rember is being to far north.
Now that the rainy season looks like its past looks like I can finally splash the boat and stop boating in my head and cruise for real. Thank again. John G