GPS Plotter

[patria]

I am trying to choose a GPS plotter to install on a yacht which currently has a GPS transducer delivering positional info to Autohelm Multihead Display units in the cockpit. The boat is in Holland and I will not get an opportunity to check the details of the GPS type until I go there in advance of the return journey to Ireland. Since the transducer is delivering positional info to the Autohelm units I am assuming that it must be presenting through an NMEA interaface. Therefore I am assuming that if I purchase a GPS chart plotter which takes positional information through an NMEA interface I should be able to connect it to the transducer. I am considering a colour Garmin GPS Plotter for example.
My question is the validity of my assumption that if the Autohelm display units are being delivered positional info therefore an NMEA interface is being used and therefore ANY GPS plotter that has an NMEA interface will be capable of connecting to this (unknown) GPS transducer, or from the last daistchained Autohelm unit.
Secondly what type of cable do I need to connect the two?
Thirdly are the power connections to drive the GPS plotter separate top the NMEA interafce?
What type of plotter do people recommend??


<hr width=100% size=1>

 

[Talbot]

I did not buy a garmin a couple of years ago, because I was worried that they would not support the older chart formats. This has now happened, so you cant rule out the same thing happening again - so IMHO DONT BUY GARMIN.

I have a Navman 5500 plotter which uses C-Map and am very happy with both.

<hr width=100% size=1>

 

[johna]

Why gamble that anything you buy will operate with the present system such journeys have been made without chart plotters.. Buy or borrow paper charts for your route and then decide on the chart plotter to buy.

<hr width=100% size=1>

 

[bob_tyler]

I also have a Navman 5500i - the internal aerial model. It works perfectly below (glass fibre) decks under a solar panel which is immediately above the plotter on deck.

Why bother with an external aerial and the wiring it involves?

An excellent piece of equipment.

<hr width=100% size=1>

 

[Guest]

It may be Seatalk and then you are 'stuffed' to put it mildly ..... but most likely NMEA.

Latch on to the GPS group ..... see my 'signature' at bottom of post and that is the address ..... try and give more detail such as make or model of GPS sender etc. and I am sure that someone on the group of near 100 members can help.


<hr width=100% size=1>Nigel ... and of course Yahoo groups :
http://groups.yahoo.com/group/gps-navigator/

 

[Talbot]

I have mine sited so that I can see it from the helm position and read it on the way to the chart table. I went for an external aerial, as a handheld had shown some issues about reception in the area I wanted to site it.

<hr width=100% size=1>

 

[extravert]

Raymarine's GPS transducers come in two versions, one that outputs NMEA data, and the other Seatalk. Mine is a 2000 model. The two versions are identical to look at from the exterior as far as I can tell, looking at the manual. The colour of the wires in the cable is different for the different types.

If you did buy a plotter that requires NMEA, and found that you only had Seatalk available, you can get a Seatalk/NMEA bridge much cheaper that the official Raymarine one, for example...

<A target="_blank" HREF=http://www.tklinux.de/>http://www.tklinux.de/</A>

(Click on English top left, then scroll down right area until you see NMEA bridge).

<hr width=100% size=1>One day, I want to be a real sailor. In the mean time I'll just keep tri-ing.

 

[BigART]

A Yeoman plotter with paper charts may suit your needs. Never a concern about obsolesence.

<hr width=100% size=1>

 

[duncan]

Firstly, assuming you have an NMEA ouput - whilst the NMEA message standards work across units there are different ones adn you will need to ensure that the format of the one being sent is the same as the one expected. Usually this can be done pretty easily in software. I had this issue with a JRC radar a couple of weeks ago - a Garmin unit was happily chatting to a Lowrance one but the JRC didn't like it at all. Switched the output message from the Garmin to an earlier one (from drop down menu) and the JRC joined in just fine, whilst the Lowrance didn't seem to mind at all. Much the best to use the newsgroup Nigel refers to for info on this once you have details of the units you wish to use.
I would also point out that you will almost certainly get an new arial with the plotter and it wouldn't be any great deal to wire that in anyway. Having 2 sources of position data can't be a bad thing and you may even be able to use either to power the auto helm or plotter.......
Secondly re cable - you will normally have to connect the data +ve from the output unit to the same on the plotter, and connect the data grounds together. IN some cases the later is only the power negative, sometimes it is seperate. Manuals (plotter) will cover.
Thirdly - yes. You will have a red and black to wire into the boats +ve and -ve.

Re which plotter - big question. Garmin's move from Navionics to their own Blue Charting, and the resulting discontinuance of support for the old charting only a couple of years after they stopped selling the units has upset some - see another post re Garmin on this board about a month ago for more details. I have both 215 and 225 plotters with a load of the old charts but don't feel overly hard done by. Generally electronic charts are now pretty cheap, as are plotters.

With reference to the comments re Yeoman, paper etc their is no comparison IMHO with a piece of equipement that, at a glance and at the helm, can give you your position on a chart in any conditions. Firends have recently got Lowrance Global Map 5000C units with a Navionics Gold chart and are very pleased, the Garmin units with BlueCharts are also easy to interpret and use. If you are planning to mount in the cockpit you will find most of these fully waterproof as well.
If you only want to use at the chart table (or at home) then a laptop running software using C-Map etc is probably a better chaoice as you have a bigger screen and generally more functionality.
Hope this helps and have a good trip.

<hr width=100% size=1>madesco madidum ..../forums/images/icons/smile.gif