It's a very pretty site for those on land but there's no way I could use a site that's that graphic heavy while aboard a boat. There just isn't the bandwidth, whether you're at sea or in an anchorage using a mildly dodgy 3G connection.
If you look at how most sailors get their weather forecasts they either come via GRIB files that can be loaded up on a laptop, or just text files of weather forecasts.
If you check the weather page on the wiki -- http://www.cruiserswiki.org/wiki/Weather
-- you will see some examples of good places to get weather. For example, I can send an email to "email@example.com" with the contents "send nadi.tong" and it will send me back a text email of the weather conditions in Tonga, as produced by the Fiji Metservice based at Nadi.
Websites with background maps and lots of flashy graphics aren't of any use to a mariner. I've previously raised this issue about Metservice NZ -- their weather forecasts (apart from being hopelessly inaccurate) are only available via the web site if you're able to pull down a map in a pop-out window and click on a region. Not something you can do while off shore relying on a sat phone for your connection.
Many cruising sailors, while at sea, have access to email only -- e.g. via sailmail/PACTOR or WINMOR. Those of us that do have internet access usually have a very low bandwidth link -- 128kbit/sec at best, and 9.6kbit/sec (dial up over satphone) being the most common.