Garmin 545s - not getting accurate readings!!!?

tphinney

tphinney

New Member
May 25, 2007
558
Tampa Bay
Boat Info
240 Sundancer 2004
Engines
5.0 MPI w/ Bravo III
So I completed the install on my 545s on the top of my helm with it recessed just under the wind screen so as to prevent from taking a direct hit when I take a wave over the bow ( yes it has happen in the past):thumbsup:. Now sice my GPS76 has always been so accurate. I assumed that the NEW 545s would be as accurate or better. NOT SO. Last night as I sew based on the chartplotter that I was in the channel; I run aground in the mud :smt089. when I realize what happeded I notice the channel marker 100 to 200 yards to port. I'm WAY out of the channel.

then today as I am head out agian instead of showing me in Channel A. it's shows the boat Icon on a Road next to channel A about 200 to 300 yard to Starboard.

Now I don't have an external antenna. I do have a good signal from more than 3 satelites so what gives????

will the external antenna help or do I have a BUM unit????

expert advice welcomed.

Also since I ran into the mud at about 24 MPH last night should I have the drive pulled to check it. I did take some paint off the lower skeg and I don't need to polish my props anymore ( no nicks of dings that I can find)...
 
Do you have the proper mapset loaded? My Garmin GPSMap 276 will do exactly what you describe when I have the City Navigator map loaded.
 
each time I was way off I had the view zoomed in to at least 500 ft and it's got the G2 vision map source loaded.

it seems to be better behaved once i'm zoomed out to at least .2 miles. which is awful for running channels.
 
May be a dumb option, but if you still have the GPS76 I would try running them both to make sure the new 545 is working correctly.
One on my 1st thoughts was like "rktktpaul" asking about the wrong map. Does your 545 have an auto/car and marine mode. My 276 will be off if I forget to put it in marine mode when I'm on the water. Even with the chip in, it was still using the auto/car maps.
 
It's the unit right Beneath the windshield Frame?
It may interfering and limiting the sattelites it's searching for lowering accuracy.

I located mine here
GPSInstall4-22-081.jpg


and I think I recall seeing 5+ satellites showing. I zoomed in to a local marina and it showed me at the dock in the correct spot. If you have it below the windshield frame you may have a signal issue
 
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I have a similar probablem with mine it's off east to west but north and south seem fine and I have 6 satalites locked in I've tried finding a solution but havn't found any mine is a Garmin 3205 with the G2 Maps
 
Have any of you called Garmin? I don't have the 545 or G2. I have a 276c w/blue chart data cards. I will say I was suprised with the accuracy but have found errors in cartography. To follow/navigate visually off the cartography and run aground when channel markers are clearly insight means there are changes to be made in how you use your chartplotter.
 
The 545s is a marine coastal unit only no protable road version.

it is mounted up under the windscreen slightly, but when I show the sky view I see six to eight satellites with an error rate of about 8 meters.

the grounding took place a night and I was following the chartplotter because this canal runs right next to the courtney camble cuasway (I was head for dinner at Bahama Breeze) and you are head on to on coming cars. very hard to see the marks with head on lights shining in you're face. it wasn't until after the grounding that I saw the canal marker.

Morph;

do you have an external antenna? the 545 has an internal, but might add an external to improve accuracy!?

I'm wondering if CENTCOM is playing around with the gps accuaracy in the Bay Area?!

Todd;

since you and I have the same unit I would ask that you double check you accuracy while under way as your going by channel markers see what the chart say's and get back to us....

back to rant....

the funny thing is if I am at say 24MPH +- and zoomed out to about .2 miles it looks pretty accurate or if I am docked and dead stopped. but if I zoom in to 300/500 Ft and/or going slow it's way off. As I was cruesing the beach at Egmont Key it had me on top of the Island.

Other part that concerns me is the charts are from 2005 and there are no updates on the Gramin site?!

I'm not very happy right now. not to mention that I may have to get my stern drive pulled and checked.

any way...on the positive side I ran with the new Simrek drive shower in place and I noticed that my overal engine temp was down a bit to 158 degrees..from 165 to 170. this is a good thing. cooler drive and motor well worth the $200+ I paid for it. ( agian when I get the time I will put a write up together on the latest mod's)
 
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tom
out of curiosity, does that unit come with an internal antenna and an option for external antenna, or did you buy it specifically with internal antenna. i have a garmin GPSMAP 492, which was available as internal or external antenna models, but there is no provision for adding the external antenna if you bought the one with the internal antenna.

you should have a screen that tells you whether you are WAAS enabled. are you getting that message?

cf-lg.jpg
 
545 has an internal antenna with a jack in the back to add an external (mine should be arriving from BOE in a few days). It should probably be capped off (the jack, when not in use).

However, as a mountain climber that has used GPS for years, I can testify to the fact that cartography can sometimes be less than perfect. I was at the top of a mountain, 12 sats, locked, averaged, WAAS running... and my map said I was half a mile from the summit.

You should have a chart of the area. Best to take a look at the lat/lon coordinates from the GPS and plot them on your chart... that will tell you if you're having an error with the GPS providing an accurate location. If the lat/lon are right on, then it's probably the chart software that you have, for that area... And yes, the NOAA charts could have an error, but I'd expect that to be minor for this purpose.
 
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Tom,
Last weekend I was checking my bearings and surrounding markers and I was impressed with the accuracy. I would call Garmin and let them know and see what their troubleshooting responses are.
Best of luck

Ron,
the 545a has an internal antenna with an external optional to add.
 
Ron,
the 545a has an internal antenna with an external optional to add.
Click to expand...

nice feature. being that mine sits about 12' above sea level with only canvas in the way, i get a real quick fix but it'd be nice to know you could add the external if it was necessary. that's what you get for buying a newer model and spending an extra coupla hundred clams!

occasionally mine will show me riding over land, but that happens only in certain areas when the channel is 50' wide and land is 15' away. other than that, i've never had a discrepancy much more than a few meters. your problem definitely warrants a call to garmin. i've dealt with them over the phone before (to order a card reader and then return the wrong one i ordered!) and they are easy to get and pretty knowledgable.
 
You have some big coconuts to be cruising at night at 24 MPH w/o radar especially into car headlights where you can't see the buoys! :wow: If you have it zoomed into 300' how do you even know which way to go? I'm glad you hit the mud and not a daymarker or stranded bay boat w/o lights! Be careful out there.
 
i sure hope you had your seatbelt on.:smt018
 
tphinney said:
Morph;

do you have an external antenna? the 545 has an internal, but might add an external to improve accuracy!?

I'm wondering if CENTCOM is playing around with the gps accuaracy in the Bay Area?!
Click to expand...

Yes mine has the external antenna. I tried contacting Garmin 1 time about it and the first thing out of their mouth was oh you need a map upgrade it will cost you $$$$ you can buy the memory card with the update or you can buy the blank memory card and the usb card reader and get the update free. I just hung up.

admin said:
You have some big coconuts to be cruising at night at 24 MPH w/o radar especially into car headlights where you can't see the buoys! :wow: If you have it zoomed into 300' how do you even know which way to go? I'm glad you hit the mud and not a daymarker or stranded bay boat w/o lights! Be careful out there.
Click to expand...

I'm very familar with exactly where he it talking about. I've only met Tom once but I'm 99% sure he knew what he was doing just the GPS screwed him up from doing something he's probably done 100 times.

This particular area is the north/top of the Tampa Bay where it is basically waist deep unless your in the channel and even then you gotta be careful.
 
I know someone that used a GPS to navigate home in the dark one night on the James River... they were very familiar with the area also... Hit a day marker at 30 mph, carved a 12' gash down the hull and sunk the boat in less than 2 minutes. One person had a dislocated shoulder and the 4 adults on the boat were rescued an hour after the boat sank... by luck...
 
I have a 540 and just got back from a 120 mile trip tonight. Accuracy was about 6ft for the three days with an internal antenna. I did not check the satellites. Only one time did I recall the unit giving me a bad location and that may have been because the buoys were moved, not sure.

I did not realize the map was a 2005, oh well.
 
actually the biggest danger in the upper bay these days is all the crab pots that have shown up in the last year and up here a 240DA is a big boat most folks run around in 16' flats boats and stay close to shore, 99.9% of then all run for shore as soon as the sun starts to set. it's like the reverse of vampires with the dawn. it's amazing...at night it's actually really relaxing versus the day time.

So Morph how old is your unit and what year is the base map that they told you; you needed to buy a new map?

Also before i forget. Any suggestions on weather i should have MM pull the sterndrive and check it after a grounding like this. I went in mud, it toke the paint off about 2-3 inches of the lower skeg; but I didn't notice any vibration or ill efects other than my own palpitations....
 
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Four Suns said:
I know someone that used a GPS to navigate home in the dark one night on the James River... they were very familiar with the area also... Hit a day marker at 30 mph, carved a 12' gash down the hull and sunk the boat in less than 2 minutes. One person had a dislocated shoulder and the 4 adults on the boat were rescued an hour after the boat sank... by luck...
Click to expand...

dark and 30 mph is just crazy....don't you think?
 
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