Whats the differece between marine and auto gps units?

G

Gerry

Well-Known Member
Joined
2 Jan 2002
Messages
1,537
Location
Devon
www.gerryantics.blogspot.com
Our Garmin 152 gps is on the blink and when surfing for a new one I see an enormous difference in the cost between automotive and marine units.

All I really want to do is display a lat and long..... so would an automotive unit do this, even when crossing oceans?
 
If all you want is lat/long ok. Check that the unit will display it adequately.
The rest of the road navigation software will fight to get your boat onto the nearest road. You will not have any real navigation assistance out at sea, just position data.
 
You want a waterproof one.
better a secondhand marine unit than a new one that will die from damp in short order.
A new Garmin handheld with 12V adaptor is pretty cheap.
 
I think there are still basic 'lat / long and a few waypoints' type marine units available, might be worth looking at new kit on E-Bay; or a decent handheld ( marine ) gps with separate external aerial & power supply from boat ?

I would dearly like to be able to download Brian Blessed or John Cleese as the voice of my boat gps though...
 
As far as I am aware.. The Marine GPS is interfaced with the oceans/seas and the land based
GPS is interfaced with roads/streets. I do not believe they would give such accurate readings as the marine ones. Our very first gps was a garmin one from a jumbo 747 it was accurate to within 1 meter. As they were used to find the planes parking spot. long time ago. OK I stop now.

Peter
 
Good point about the difference between nautical and land miles, I hadn't thought of that one!

Am still shocked at the difference in price here, from £60 to around £250! Is this the same old story of anything marked marine or do you think there is a real difference? The GPS dongles at £15 seem an amazing buy. Your thoughts?
 
Gerry said:
Our Garmin 152 gps is on the blink and when surfing for a new one I see an enormous difference in the cost between automotive and marine units.

All I really want to do is display a lat and long..... so would an automotive unit do this, even when crossing oceans?
Click to expand...

If you go to the Garmin website you will be able to see the full specification for the instruments that interest you.
You will also be able to download the owners manuals and find out if/how they do what you want.
All the facilities of an automotive GPS would would put me off if all I wanted was Lat and long but I guess you could use it in the car when not needed on the boat

For just finding Lat and long you could consider the lowest priced hand helds maybe buy two so that you have a back up if one fails


http://www.garmin.com/uk/
 
Gerry said:
Our Garmin 152 gps is on the blink and when surfing for a new one I see an enormous difference in the cost between automotive and marine units.

All I really want to do is display a lat and long..... so would an automotive unit do this, even when crossing oceans?
Click to expand...
To the best of my knowlege there's no such thing as an ""auto gps unit". If you mean a "satnav", it's an entirely different thing to a marine gps, such as the Garmin GPS 72/76. Differences are too numerous to mention. Perhaps someone who owns a "satnav" can tell us what the display shows when you're 200 miles away from the nearest road.
 
Gerry said:
While I'm at it has anyone any experience of USB GPS dongles which come as cheap as $17 on ebay and claim to be compatible with navigation software ef open cpn??
Click to expand...
Just received mine in post from Hongkong-£20 including delivery etc.
The G.Mouse-BU-353
I bought it to run Seaclear and my Admiralty plotter on a laptop.
It includes a driver and a neat little programme that delivers basic GPS info to your laptop-lat and long;bearing and speed plus display of receiving sats.and strength.
(sorry about the c...nokia pic quality)
Its really good and whilst its got a magnet to attach to car roof or similar it will aquire enough satellites to work half strength within two decimal places of seconds through a slate roof ceiling,floor and ceiling!
I have yet to try it below deck but I am sure it will have no problems aquiring 7 plus sats with little signal loss.
Oh and yes it runs Seaclear and OpenCPN no problem.
 
Last edited:
Yes went to the garmin site but to be honest it totally baffled me! We are a bit backwards on our boat and use a minimum of electronics, I want to see a lat and long and the compass heading on the one we have (152) is useful to make sure we are still heading in the right direction!

We carry 3 handhelds, the unit that is failing is the one on the navigation station. We like it as it has a large display that we can see from our sea berths when on a passage...To pay £300ish for that when an auto one is around £70 seems a bit daft:-)

I will send Garmin an email and see what their response is:-)
 
Thanks Elton that, I think, is what I was trying to ascertain! So a car satnav would not give me the info that I am looking for at sea ie Lat and long ?

What are the basic differences then between satnav and gps? In my ignorance I thought they were the same thing....
 
I assume that you aren't talking about a unit built into a chart plotter (where extra cost is for charts, display, complex software). Perhaps "interfaced with streets" above refers to maps vs. charts and that is true for plotters but not basic units.

A very basic marine GPS units just sends NMEA data to a plotter and is a waterproof box with no display. More complex units have a display and software to add waypoints, rolling road navigation etc.

If you just want to buy something to simply relay GPS co-ords to a PC based plotter then a "dongle" will be fine. There are some things to watch out for (e.g. auto-shutdown) but pretty much anything will work. The data isn't NMEA, just a stream of co-ordinate data, so PC software like OpenCPN will read it.

Check this discussion http://www.ybw.com/forums/showthread.php?t=307659

You could take any TomTom or similar road unit and set it to display Lat/Long and plot that on a paper chart. In fact, you could also enter waypoints (i.e. Favourites) using Lat/Long and could create a Route (i.e. Itinerary) to follow. It would be very clunky but position accuracy would same as a marine unit.

If either of the above aren't what you need then you'll have to pay for marine unit with extra features needed.
 
So ffiil, was your mouse sold for marine or auto use? you imply that the magnet for sticking to the car roof means it could have an auto application but you are using it on a boat, is that right?

Oh dear I am getting confused now! So is this Satnav or GPS???
 
Ok Mistroma that's really helpful.

Seems that we do it the 'clunky' way already! No chartplotter on this vessel all paper charts.
So probably an auto unit would do me very well at a far cheaper cost. Many thanks.
 
Gerry said:
So ffiil, was your mouse sold for marine or auto use? you imply that the magnet for sticking to the car roof means it could have an auto application but you are using it on a boat, is that right?

Oh dear I am getting confused now! So is this Satnav or GPS???
Click to expand...
Some of the post above are referring to a GPS "puck". This is a device that has no display, and is designed to plug into a laptop loaded with navigation software.
 
I meant to say that the TomTom I use is actually a program running on an old HP PDA with Bluetooth GPS. At sea it just shows lots of blue as expected but "really close" to land it will sometimes decide you are on a road. i.e. If GPS shows you are 50m offshore and there's a road along the coast the sotware over-rides the GPS co-ord. and put you on the nearest road.

It can be configured to show speed, distance, compass and so forth. Of course you get miles and degrees True. Smart phone with built-in GPS should also be able to display similar information. Perhaps you can download some freeware for that if you have one.

I've tested mine at sea several times as my backup to main plotter's GPS and sep. GPS feeding DSC VHF. OK, I'm paranoid and also have 1 fluxgate, 2 steering and 1 handbearing compasses plus sextant.
 
You must log in or register to reply here.

Other threads that may be of interest

Y
The Seafarer 700 and NASA clipper sounders saga
Replies
10
Views
432
Dellquay13
Dellquay13

Share this page

Top