JRC Plot 500F issues

[Damien Day]

Gday Guys and girls, Im hoping someone out there can help me with my JRC plot 500f plotter/sounder combo. The issue is that the plotter shows my position 150-200 mtrs out to the chart. I have tried different charts with the same result. There is nothing in the manual that I havent tried, and am still unable to plot the correct position in reference to the chart (If I put in a coordinate eg 20 24 150 by 116 32 414 it takes me there no worries but I will "pass" through Islands on the way, even though Im on the water). Any info or advice (excluding binning it!) will be greatly appreciated.

[Stuie]

The same thing happens on my Lowrance unit. When running up the creek at 1770 it quite often plots my course over bits of land. The creek is quite narrow in places and we do run close to land so I'd say about 20-50m out of whack. I've never really worried about it because I only fish offshore. I guess it would be a drama fishing in the creek or out around a lot of islands. I'm not sure why it happens but suspect the maps are put into the units slightly off where they should be. Just another good reason not to rely on a chartplotter as a navigation tool.

[oddbudman]

I think you should get a reference map and compare it with the GPS info your sounder is giving at a fixed location. Ie pick a location on the reference map, check its GPS coordiates and compare that with your sounder. This way you can see if the GPS data received is accurate.

My friend runs a JRCPLOT 500F and we have not seen any mapping problems from southport to noosa.

cheers,
oddbudman

[Homer_Jay]

I also have the 500f, i had problems with the track being out by up to a couple of hundred meters. I just had to change the setting of how often it updates the info from the satelites. I changed it to the highest setting and now its spot on.

Imoprtant when comming back through the bar on your marks.

[Isaac]

I have a Plot 500 and only use it as a sounder (ie no GPS antenna) as I have a lowrance plotter with navionics maps, I was wondering what you guys think of the 500F as a plotter as I'm thinking about buying the antenna and card as a backup for the lowrance. Is it easy to use, are the C-maps any good? Cheers