No I cannot overlay Grib direction arrows and isobars over C-maps. I can in Maxsea
but not OpenCPN. I use Gribs as follows in OpenCPN. I click on the Grib icon and select the appropriate date/time file. All data boxes are ticked. Wind
speed, direction and pressure boxes contain data and change value when the mouse pointer is moved over the chart. But, no data is displayed on the chart. Using Win7 Home Premium 64 bit, Intel core
processor, 8 Gb of RAM and a Nivadia GeoForce video card. Ugrib works fine, but not open CPN
. I hope this clarifies my problem.