a. "If the unit has too many waypoints and the memory has not been purged the unit slows down, resulting in a slow scroll speed."

On a Touch how many waypoints are to many?

3." As far as the ONIX goes - I forgot that it has a chart speed setting, and I should have turned it down to look like this -
That in the 25-30ft range is a thermocline."

I saw that in the first image but didn't realize it was the thermocline. Strange that it's clearer than the water above or below it.

Thanks for the detailed reply.