Garmin GPS Chartplotter?

[Steelshooter]

I've been looking at GPS Chartplotters to install on my Catalina 30. Currently there is no navigation gear installed and I've been looking at for something that will provide good service for the type of sailing that we do. Money is very much a factor and I believe that the Garmin 531 should fit the bill nicely. Our boat is a Great Lakes boat and there is no chance that she is going to be sailed to the deep blue. We are mostly day sailors and will be taking a week or two vacation a couple of times a year sailing around the Great Lakes.

So do you all think the Garmin 531 is a good choice?

[CarlF]

The Garmin's are great units at excellent prices. The only caution I'd raise is that the 531's resolution is 230x320. I'd go to a West Marine and compare it to one of the slightly more expensive Garmins (like the 526) that has 480x640 resolution. I find it hard to read the chart text (like buoy numbers and depths) on the lower resolution units.

Also, if you don't have a depth sounder get one of the "s" versions. You don't need to drill a hole in the hull for the transducer. Just epoxy it on the inside in a place where there's no core. Search the web for detailed instructions.

To get the best price, wait for a new model to put the old model on deep discount. Garmin is sure to release some new models before it's warm enough for you to sail.

Carl

[Martinini]

I have a Garmin 440S with bulit in charts for the US and Bahamas and I love it.

[jfssail]

I agree with CarlF, The garmin units are excellent, but your low price 530 series unit may not have the best resolution. Two years ago I bought a factory reconditioned 172C unit on E-Bay for about $250. It came in an original box with all accessories and instructions. This unit came with built-in antenna with a 4.5", 320X320 pixel screen. I find this resolution to be excellent. One of my concerns with the newer Garmin units is that they require the newer Bluechart G2 vision card charts, which list for $300. The 172C unit took the older Bluechart MUS series. cards, which can be purchased new for $130, or as low as $30-50 used on E-Bay. They list for $160
I assume you intend to sail in Canadian waters, I don't think the built in charts that come with the new 530 units cover Canada. That was one of the reasons I purchased the older Garmin unit.
I usually spend 8 weeks in the summer sailing Lake Huron and the North Channel, and am very happy with my 172C. Keeping my eyes open this winter on E-Bay for a Lake Michigan Chart for my Garmin. Planning a trip next summer to the Door Peninsular next summer.

Jack F Stewart
1993 C36#1233 "Windancer"
Port Clinton, OH

[Steelshooter]

This is why I just love this site, so much valuable information.

I had never considered the resolution issue and can see where this could be a problem. I hate buying something only to find out I wished I had upgraded in the first place. The 526s looks like it will fit the bill nicely. I have a Raymarine depth sounder but it is mounted on the cockpits forward bulkhead and is hard to see, mostly because someone is always sitting in front of it. I like the idea of a "s" model so that all of the information I need is displayed right on the pedestal.

One other thing, I see the there is a minimum distance that the GPS is to be mounted away from the compass. In this case nearly 24 inches. Most boats I see have a whole panel of electronics mounted just above the compass. Is this really a factor with this GPS? I know electronic fields can play havic with compasses but do these units produce that strong of a field?

[CarlF]

In my experience, a beer can in the skipper's hand is a bigger problem to the compass than the GPS. To be safe, turn it on before mounting and move it around near the compass.

You'll also find that the GPS compass information is more accurate than your magnetic compass (although it's easier to steer a steady course to a real compass card).

If you do go to Canada, make sure you have factored in the add-on cost. These can really add up. You don't need the 3D or satellite images but the "worldwide base map" ain't enough.

Carl

[scubasteve]

In my opinion, Garmin electronics are well made and very intuitive. I do not have any complaints of their GPS/Chart plotters. Resolution is a bit low but never enough to be issues.

Some other area’s like sounders are decent but may not be the best.

I would buy another Garmin GPS/Chart plotter without any worries.

[Martinini]

Generally compasses have adjustment screws to compensate for errors created by electronics mounted close by as well as metals that are magnetic. Another consideration is if the chartplotter is working you won't really need the compass. If the plotter dies then there will be no electrical field to affect the compass. The distance is required for compass operation unless the compass is compensated. Compensateing the compass isn't that hard. Make a mark with a grease pencil at the North pointing mark or which ever point is convenient. Install plotter and turn on, and watch the needle move! Once the needle stops use the adjustment screws to move it back to the grease pencil mark, and you wll be good to go. Remember the deviation or make a permanent mark at the point the needle travels to before you adjust the compass. That will tell you how many degrees the compass will be off if you lose, or turn off the plotter. Much simpler to find a spot 24" from compass to mount plotter!

[Ziggy]

Originally Posted by Martinini

Another consideration is if the chartplotter is working you won't really need the compass.

It's very difficult to steer by the gps without a heading sensor or a compass. You do need a compass even if the gps is working perfectly well. It is true that compass deviation is not as critical if you have a working gps, but you may find the deviation confusing if it changes depending on whether the gps is on or off.

[Martinini]

My Garmin has a built in compass, but I agree it is a pain. Thats why I found a spot the required distance to mount my plotter from the compass. Remember you can go up, down or sideways from the compass.

[scubasteve]

Your compass should be mounted to function correctly with the electronics on or off. When you really need to rely on the compass, you need the confidence that it will lead you in the right direction…..or it’s useless.

[Steelshooter]

Well while I still have you all on the hook so to speak I have yet another question. I have a Raymarine ST-40 bidata depth and speed display mounted to the forward cockpit bulkhead. Is there any way to link these two together to get speed and depth displayed on the Garmin GPS? What about apparent wind displays?

You all have been a God Send for this newbie sailor.

[CarlF]

About a year ago the Ocean Lines blog showed helm design suggestions submitted by Furuno, Raymarine and Garmin for a 53' trawler. Here's the helm mock up picture that Garmin engineers submitted. It doesn't seem that they were too worried about putting Garmin chartplotters near the compass. Maybe you need three chartplotters all around the compass to balance the magnetic fields out

Garmin Outfits the new Kadey-Krogen 55′ Expedition | OceanLines


Oh - I'm pretty sure that the Raymarine 40 series doesn't output anything that could be interfaced to the Garmin



Carl

PS - if the compass in the Kadey-Krogan picture is a KVH electronic compass - my apologies to the Garmin engineers...

[sck5]

I have one of the higher end Garmin units - You do NOT need the bluechart g2 vision cards for them. They are an option but not required. They will also take the cheaper bluechart cards. None of this is cheap but the more expensive g2 vision cards arent a requirement (as far as I know) on any of them.

Better than any of the cards is to get one of the units preloaded with all of the USA and Bahamas charts. You can save a lot of money that way. You wont get the great lakes or inland waters that way, or anything further afield than the Bahamas, but most people dont need that anyway

[sandy daugherty]

Read the Garmin literature pretty closely. The built-in charts may or may not cover the Canadian side of the Great Lakes. I had to buy another unlock code to put the Northern Channel of Huron on my gpsmap 76cs, but it was worth it, sailing up there was exquisitely beautiful!

Last year's crop of Garmin 400/500 series chartplotters will be discounted now or soon because they have introduced newer versions with faster processors and N2K connections; probably not something you would need.

A caution about adding another depth transducer over your ST-40. There will be contention between the two because they emit at the same frequencies. It is likely you will have a problem with one or both.

Raymarine does have a little black box that will let your seatalk instruments talk to your garmin. With that you can display water depth, speed and possibly wind data on a Garmin Chartplotter. Its called a Seatalk/NMEA/PC interface (or something like that) and its reasonably priced.

Go to a store and look at the Garmin 400 series and 500 series together. Remember that you will be seated or standing fairly close to the helm when you are using it, so see if you can get by with the smaller screen. It is cheaper and uses less power, but it has all the functionality of the 500. Learn what the differences are between the different units; it has to do with the resolution of the screen and which charts are preloaded. You can add Canadian charts from the $160 Bluechart CD and load them into either of these chartplotters wih common SD memory cards.

What ever you buy, make sure you connect it to your VHF radio for DSC and the Coast Guard's Rescue 21 service. This is a no-brainer. No DSC button on your old VHF? Buy a new radio too. BEFORE you spend another dime on the boat! Yes dear, before you buy new curtains....

[drum roll] AND, if you have an autopilot, both of these will drive it! SLICK!!!