GRIB - I guess I really dont know how to download GRIBs .... any sources you can recommend (of course I have a "Mac" so I'd need something compatible for that OS platform. - thanks.
Go to saildocs.com and download their Viewfax grib viewer. Also get documentation from their site. Evans Starzinger also has info at his site, I think it's BethandEvans.com
It's amazingly simple, for example, you just send an email to firstname.lastname@example.org
with something like the following:
send gfs:40N,45N,65W,72W|0.5,0.5|0,6,12,18,24,30,36,42, 48,54,60,66,72,78,84,90,96|WIND
This will request data on a 1/2 degree grid over the area covering 40-45N, 65-72W (happens to be an area I cruise, southern new england to maine and nova scotia), requesting wind predictives in 6 hour increments. There is other data, such as pressure and wave height, available, but I find wind most useful for route planning.
The GRIBs are free, are very small files, and the saildocs email robot responds very quickly, usually a minute or so. Their viewer is simple but very useful, however the GRIBs can also be used by many PC navigation programs.