Passage weather is useful for forward looking forecasts (up to 5 days) but you can't save the information. A better choice could be to use zyGrib link
which does the same stuff but you can save the files. Similar is UGrib link
You have many choices for weather forecasting while at sea including radio based info and weatherfaxes.
Many cruisers use grib files obtained via radio based email. Grib files are available via email or ftp. Free. Take a look at saildocs.com
The above link includes links to other sources of Grib files.
Inmarsat Coverage Map
METAREAs are usually divided into sea areas for weather forecast broadcast using INMARSAT-C, NAVTEX, VHF, MF/SSB and HF/SSB radio.
METAREAs or NAVAREAs are regions of the oceans for which specified nations have the responsibility for the co-ordination of the provision of meteorological and other marine safety information. For METAREAs look at the above link and image of a coverage map which shows all METAREAs worldwide. METAREAS I, II, III and IV, covering the North Atlantic and the Mediterranean are the responsibility of the UK, France, Greece and the USA respectively.