C Maps inaccurate?

ziggy

Well-Known Member
I was prawning in the Saanich Inlet the last couple of days and was using my new Lowrance Elite FS. Not sure if I have done something wrong on my set up, but man my bottom readings were totally out to lunch with the bathymetric chart. I’m sure the sounder readings were correct because I verified them with my other sounder, but the chart contour lines were no where near accurate, at times 100 feet out! Anyone else find the bath
 
I've navigated BC waters for almost two decades using C map (Furuno) and I've never found those types of discrepancies. Did you try resetting the zoom settings on the chart plotter?

I have had discrepancies with navionics, however--- I've seen misspelled Islands and reefs showing on the chart that were several 100 yd in a different direction. But i've never seen those type of discrepancies with C-map
 
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I've navigated BC waters for almost two decades using C map (Furuno) and I've never found those types of discrepancies. Did you try resetting the zoom settings on the chary plotter?

I have have had discrepancies with navionics, however--- I've seen misspelled Islands and reefs showing on the chart that were several 100 yd in a different direction. But i've never seen those type of discrepancies with C-map
The problem was with the contour lines, they were not even close. I think the positioning was OK and know the soundings were accurate, but when for instance I tried to follow a contour line on the chart it didn’t match the soundings. At one point the chart and actual sounding were about 100 ft out. I’ll see if I screwed up a setting, it’s a new toy!
 
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