The I use the "NOAA Operational Model Archive and Distribution System" (NOMADS) as a source of both wind
and surface current GRIB files for the Weather_Routing_pi. Here is the link
NOMADS-NOAA Operational Model Archive and Distribution System
I use the Grib Filter feature on that web page. The wind
GRIBs can come from from one of the GFS data sets, and the surface current can come from an RTOFS data set (near the bottom of the NOMADS page).
These RTOFS parameters must be selected for the surface current:
Check the box next to "subregion" to download a smaller region than a whole ocean and fill in
Longitude and latitude numbers are specified in degrees. West longitude or south latitude require a minus sign.
You will find that each time you select the parameters you can download a forecast
for a single
time. Try it a few times, but you will find it easier to ask for the URL that gets the download. A batch file can be built using the URL as a template with each line in the batch file calling out a different forecast time.