Using Your AP on Routes

[bayview]

How do you use waypoints when crossing the stream without winding up following a curved route?

 

[syjos]

I don't use an automatic route creation tool; Auto-route.

I prefer to create a route myself taking into consideration:

Current direction and strength. Favorable route through strong current areas.

Boat traffic. I create a route to stay away from heavy traffic areas and where small boats congregate and fish.

Attractions along route. Travel closer to shore to see attractions.

Transit windy area. Create route to favor lee shore.

Crossing straits and open water. Choose the most comfortable route in relation to sea conditions and direction.

It doesn't take long to create a route and name it. I save every route created. I can copy an existing route, join it to another route, add waypoints to the route, move or delete waypoints etc. I rarely have to create new routes anymore. I have route to and from everyplace we've traveled since the 90's. I copy and modify an existing route and rename it.

To make searching for a route easy, each route has a descriptive name. I created folders for South Puget Sound, Central Puget Sound, North Puget Sound,man Juan's, Gulf Islands, North of Nanimo, Broughtons and North of Vancouver Island.

 

[psneeld]

Keep an eye on " highway" mode and make small adjustments, just like the auto pilot does.

 

[syjos]

When we get to a waypoint on Nav and the AP alerts the turn, we look around before acknowledging. Also if the waypoint course change is more than 10 to 30 degrees, the turn is done manually to avoid a sharp turn.

By letting the autopilt drive the boat, the helmsman can pay more attention to the instruments, electronics and the traffic. And the boat will follow the course more accurately and efficiently than I can.

 

[menzies]

How do you use waypoints when crossing the stream without winding up following a curved route?

Depends where you leave from. From West Palm we do the following.

We estimate how long we are going to be affected by the stream and put in a waypoint at the other side of the stream that number of miles south of our stream exit point (when crossing east). Then additional waypoints for your final destination - say Port Lucaya.

So if based on your speed you will be in the stream for five hours and the stream runs around 4 kts, but you are angling across it then estimate around 3 kts per hour impact. That equals aiming 15 miles south WHEN YOU FIRST ENTER THE STREAM. Then aim 12 miles short after an hour in the stream, 9 miles after two hours etc. So just adjust as you go. Sounds complicated but it really isn't.

You are still curving somewhat but unless you adjust every ten or fifteen minutes you can't avoid it.

Now there are variables in play, wind/seas/stream slower or faster so after a couple of hours you can see how you are doing and keep adjusting.

 

[psneeld]

A lot easier and WAYYY more accurate to use highway mode or track mode, etc.....than guessing Stream speed or anything else affecting set/drift.

Even easier to let AP go A to B on Nav/Track rather than just Auto and hand adjusting.

 

[syjos]

How do you use waypoints when crossing the stream without winding up following a curved route?

By using the Nav function. The AP make small correction to follow the route exactly to compensate for the strength and direction of the current. Here in the PNW, with strong currents, the Nav feature allows the boat to follow the route without following a curve or worse, a zig zagging route.

It feels strange when you are crossing a big body of water with strong current perpendicular to the route. The bow points away from your destination and crabs along the route. The natural inclination is that the AP is steering away from your destination and you want to make a course correction. But leave the AP alone and the boat will end up at the destination with minimal cross track error.

 

[danderer]

I use routes and the Nav function to follow them probably 95% of the time we are underway. Prior to departure I research and lay out the route. Then while underway you are looking it over again and can make fine tuning adjustments. It's also a very important part of planning many passages where you need to hit certain areas within a tight window of time. I can play with the departure time to get the desired arrival time at a pass where I need slack current, for example.

I think a lot may have to do with whatever charting system you use, and how easy or difficult it is to create and modify routes. The chart plotters I have owned (Raymarine C120, Furuno NN3D, and Furuno TZtouch) were all instruments of torture when it came to creating and editing routes, so I didn't use them. It was when I started using Coastal Explorer that routes because easy and useful. You just click click click with the mouse to drop waypoints along your route, and can double click along an existing route to insert an additional waypoint. I usually do a rough plot of the route first, then go though segment by segment to inspect and tidy it up. Then each segment gets checked again while underway, and any waypoints can be moved by simply dragging them. A mouse or equivalent makes all the difference in the world.

Also, once you have established routes and have run them, they become very handy resources the next time you are in the area. I have a whole bunch of them for various tight passages, and I know they are good routes. And others have given me their routes for passes.

Agree with all the above. We research and plan on an iPad the night before, load to the MFD and run. Also save a library of "proven" routes.

 

[syjos]

I think a lot may have to do with whatever charting system you use, and how easy or difficult it is to create and modify routes. The chart plotters I have owned (Raymarine C120, Furuno NN3D, and Furuno TZtouch) were all instruments of torture when it came to creating and editing routes, so I didn't use them. It was when I started using Coastal Explorer that routes because easy and useful. You just click click click with the mouse to drop waypoints along your route, and can double click along an existing route to insert an additional waypoint. I usually do a rough plot of the route first, then go though segment by segment to inspect and tidy it up. Then each segment gets checked again while underway, and any waypoints can be moved by simply dragging them. A mouse or equivalent makes all the difference in the world.


Also, once you have established routes and have run them, they become very handy resources the next time you are in the area. I have a whole bunch of them for various tight passages, and I know they are good routes. And others have given me their routes for passes.

I do the same thing. Dropping and moving waypoints is a lot easier with PC based chart plotters. Storing and cataloging hundreds of routes is easier on a PC too.

 

[psneeld]

Even hand steering or tweaking the heading on the AP....can it get any easier than this unless you go to track/nav mode?

 

[Baker]

How do you use waypoints when crossing the stream without winding up following a curved route?

The AP adjusts heading to maintain a course(over ground) to your waypoint. What you are suggesting is called "homing"....where you just keep pointing at the waypoint without maintaining a course over ground.

 

[menzies]

Baker, I think you quoted the wrong post.

 

[Baker]

Baker, I think you quoted the wrong post.

How so?

 

[menzies]

How so?

Because he was asking not suggesting anything?

 

[Baker]

Because he was asking not suggesting anything?

Well then maybe a poor choice of words on my part. I should have said "referring". What he was referring to is called "homing" if you just keep changing your heading to point at the waypoint without trying to maintain a course over ground. It will indeed be a curved course to your waypoint. Now if you OR your AP, which is what this thread is about, maitain a proper heading to correct for drift, then it will be a straight line.

 

[syjos]

Homing has caused groundings and rock strikes when the boat veers way off course and the helmsman is not paying attention, just adjusting heading to get to the waypoint.

 

[menzies]

Homing has caused groundings and rock strikes when the boat veers way off course and the helmsman is not paying attention, just adjusting heading to get to the waypoint.

Yep, though not an issue crossing the stream - the issue then is that you could end up more nose into the stream for the last hour or so!

 

[syjos]

Yep, though not an issue crossing the stream - the issue then is that you could end up more nose into the stream for the last hour or so!

The stream is the Gulf Stream? Does it run in the same direction all the time? Does the speed change from one spot to another?

 

[menzies]

The stream is the Gulf Stream? Does it run in the same direction all the time? Does the speed change from one spot to another?

Runs north all the time. The edges do shift and can be found on the NOAA weather site. As with all "rivers" the speed will be least at the edges and greatest in the middle - but you have to remember that this is a river that is up to fifty miles wide moving along at 3-4 miles per hour. It is between 2.5 and 4 thousand feet deep. With absolutely beautiful deep royal blue waters.

Because the stream's current runs north the general consensus is do not cross if any winds from the north - meaning wind against tide conditions. Clearly if they are light winds it is doable but anything over 15 knot winds can start to get really uncomfortable, over 20 knots and you are in for a beating. More so because you are running beam on to the seas to get to and from the Bahamas from the US.

 

[syjos]

Runs north all the time. The edges do shift and can be found on the NOAA weather site. As with all "rivers" the speed will be least at the edges and greatest in the middle - but you have to remember that this is a river that is up to fifty miles wide moving along at 3-4 miles per hour. It is between 2.5 and 4 thousand feet deep. With absolutely beautiful deep royal blue waters.

Because the stream's current runs north the general consensus is do not cross if any winds from the north - meaning wind against tide conditions. Clearly if they are light winds it is doable but anything over 15 knot winds can start to get really uncomfortable, over 20 knots and you are in for a beating. More so because you are running beam on to the seas to get to and from the Bahamas from the US.

Thanks menzies.

It sounds very similar to the currents here but there are not any places with current to cross 50 miles across. Usually we go with or against the current except at straits. The currents are variable depending on where we are but can get up to 7 to 9 knots at the narrows.

And we also will avoid opposing current and wind.

The water is warmer in the stream too? And does it make the air warmer too?

 

[menzies]

The water is warmer in the stream too? And does it make the air warmer too?

Ah now you are getting into a hurricane track conversation and a whole other topic!

 

[syjos]

Ah now you are getting into a hurricane track conversation and a whole other topic!

Ahhhhhh. I understand. Things are calmer and more prdictable here. Sorta?

 

[Codger2]

Even easier to let AP go A to B on Nav/Track rather than just Auto and hand adjusting.

Yes! That's what it's for!

 

[Alaskan Sea-Duction]

I have 100+ routes in my library. I use AP on routes all the time. I first create the route on my laptop with CE, then transfer it to my Raymaine MFD as a GPX file. As I approach a waypoint the system will ask me if I want to proceed. I reuse different routes and modify them all the time. LOVE my AP!! Thank you Crusty for convincing me AP was the way to go.

Rocky Pass is one place I have not been yet. Scared of it.

 

[koliver]

From all of the above, there is a big difference in the conditions in which we all travel. hose differences mitigate different approaches, so, in the words of PSN, it depends.

Personally, with a Raymarine AP, I have run enough routes to know that while doing so, if you leave the helm for any reason, at that moment, the AP will accumulate enough cross track error to need to adjust course to eliminate it. That course change will have you pointing at an oncoming boat that, moments before, you had confirmed was not in a position that was of any concern, so going below to use the head was permissible. Or worse, you are out on the side deck talking to a companion boat when your own suddenly heads right at them.
The normal "Auto" allows you to be confident that your boat won't arbitrarily change it s heading and head for danger. You need to purposely do that.

 

[CaptainSEA]

When I crossed the Pacific from Florida to Thailand on my sailboat,I used the AP on nav mode, very efficient but dangerous for 2 reasons, if you reach a waypoint and the next one is 30 degrees turn without your approval then you jib, second issue is when you need to change course to avoid a cargo or fishing boat, back on AP/Nav the boat will point to the shortest way back to the way point with a sudden turn and potential jib again...
I currently have a furuno NNet but simply use my navionics on Ipad for short cruising, make a route, turn the AP on but not on Nav mode

 

[twistedtree]

A number of concerns expressed here would appear to be AP tuning problems. You AP should hold a pretty straight course, and in Nav mode it should keep the boat on track within the limits that you set. But it definitely shouldn't drift off track, suddenly act surprised, and make a panic turn back to the track line. It should be continuously correcting, applying more of less rudder based on how far off tract it is. If your AP isn't working correctly, then you will have lots of good reasons to never use, or try Nav mode.


Now assuming your AP is working correctly, my only suggestion would be to give it a try. Everything has a learning curve, and I think a lot of people do not do a lot of things simply because they don't understand them, or have never tried them long enough to get acclimated and to appreciate the benefits. Everything seems like too much trouble until you try it and get used to it.


You never know. If you try it, you might like it... It doesn't relieve you of any watch keeping duties, but it does give you a capable helmsman to do the grunt work of steering your planned course.

 

[psneeld]

While I understand some people's concerns over AP idiocyncronies As Twisted pointed out, some can be adjusted on some machines, some rarely happen if at all unless there's a fault which can affect the AP at any time in many ways, of just a lack of understanding just how and when an AP works.

Watching how other people use an AP is interesting and worthwhile..... I am at the point of trusting today's tech with my life....more so than trusting me or anyone else to hold a steady course through thick or thin ( but not conditions that overpower it or the boat).

Finding faults with one often is not a problem with the machine itself...

 

[Woodstock]

I have used my cheap, older pilot (Ravmarineon 5000) on Track/route in a long straight canal (Alligator/Pungo for those who know it) as a test and it kept me pretty well centered for around 8 miles.

We've not yet used our AP in auto route mode, just use it for maintaining a heading.
But the statement above brings up a question. During a trip last month we were southbound on the ICW for several days so we were going against the flow of most of the traffic still migrating north. We encountered many, many boats that were tracking down the center of the channel, often in areas where the channel was very narrow where boats should be favoring the starboard side in order to allow sufficient room to pass. Many of those that we passed did not move from the center of the channel. We often had to move out of the channel in order to get by. Is traveling down the center of a channel (not favoring the starboard side) possibly the result of using an AP on auto routing?

 

[ranger58sb]

Is traveling down the center of a channel (not favoring the starboard side) possibly the result of using an AP on auto routing?

Might be, but I'd more likely guess bad manners, lack of education, feelings of "entitlement," or all of the above.

Could be some less critical reasons, maybe. Extreme caution following a channel, etc...

-Chris