One day out sailing in beautiful weather, I had a chance to notice something unusual with the
radar overlay on my
Garmin 3210 plotter using the 4 kw
Garmin radome.
I had the plotter on at the time, and while sailing a Navy sub passed by us about 1/2 mile away as it was leaving San Diego. I decided to see what the sub target would look like on
radar, so I started up the
radar. The target was big, and you could really see it moving across the plotter screen. Then I decided to put the
radar on overlay, and I could barely see any sign that the sub was even there! I switched back to
radar only, and there it was again as big as ever. Switched back to overlay, and could hardly see a target.
I emailed
Garmin support about this, and they couldn't give me any reason for this happening. I keep the software updated, so I know it's not a case of updating. I've never noticed that situation before, as I've assumed that everything I saw on overlay was what was out there...at least it appeared that way on some night runs we've made. One idea that
Garmin offered to me, was that the plotter screen might be to light to see the target (which is yellow). They think the reason I see the target in the
radar only mode, is because the back ground is black...that could be. I have not tried to darken the plotter screen yet to test that idea, but I will next chance I get.