Hi Nick,

A suggestion to add a button to download the GFS @ 0.25 degrees weather data for Primary wave mean period @ surface, which is available as per LuckGrib.

If this feature is added, both ECMWF WAM and GFS WW3 have this wave mean period data. An additional feature could then be to incorporate the primary wave mean period into the Wave table. So you can route for instance with various mean periods, eg the 3 buckets 0 to 5 seconds; 5 to 10 seconds; > 10 seconds. And adjust polars / routing.

Hope this idea makes some sense, 

Herman