Hi Jitka, Yes, that is correct you will have to use Grib1Data class directly or extend the GribGridServiceProvider class to perform your needed operations. Extending the GribGridServiceProvider class is beyond the our support so you would have to implement it yourself. I don't want to give you false hope, but maybe in a year or two when unstructured grids are implemented it may be possible to read the unexpanded grids with the CDM stack code. At this point, I'm not directly involved with unstructured grids so I might be completely wrong. Robb... Ticket Details =================== Ticket ID: EEV-923331 Department: Support netCDF Java Priority: High Status: Open