[bobetter]

HOWEVER, I find two major shortcomings:
1 - I find the lack of upper air (500mb) data a major flaw. I even got a grib with upper air data by a direct query to saildocs and openning it in uGrib. While uGrib would show the surface data it would not show the 500mb contours (which MacENC would do).

Yes, their suite of available files is limited at the moment. I'm given to believe that that will be user driven. Their forum has a "Feature Request" section whereby users can post suggestions/requests.

2 - You must be connected to the internet to get the data - their is no email delivery option. Thus its only good for short term near-shore data where you either get data before departure, or you need a satphone or other internet connection.

I think you are missing the point here. To send/receive email, one must also be "connected to the internet", how you do that (cel, sat phone,wifi, etc) doesn't matter. The downside to email is that there are 2 transactions involved-sending and receiving, both of which are time and bandwidth consuming. The beauty of grib.us is that the transaction happens in one session, you make the request and the file is immediately downloaded, either with ugrib or their browser interface. I would guess that the connection time and data transfered are less than 50% that of the email method. BTW, you specify the size of the file in the browser by selecting the compression method or with ugrib, by the connection type. Once you get the file, MacENC or GPSNavX (or others) will display it.

Still, for free it's great as long as you're coastal cruising, though a port to the Mac would be useful.

It will be just as useful no matter where you are. I currently receive my GRIBs while at sea via my Iridium and when coastal sailing via my cel.

Yes, a port of ugrib to Mac would be great... In the FAQ section of their page, they address that very issue. If they see enough interest from Mac users, I feel sure an OS X version of ugrib would be forthcoming. Make a request in their forum!!

My two cents
Scot

Bob (not affiliated with grib.us)Etter