Saildocs, a Gram Schweikert tutorial

Ben Ellison

Ben Ellison

Panbo editor, publisher & chief bottlewasher from 4/2005 until 8/2018, and now excited to have Ben Stein as very able publisher, webmaster, and editing colleague. Panbo is going to the next level in 2019 and beyond.

13 Responses

  1. I’m glad to see that Jim’s baby is now advertised for just anyone to use … it previously was for Sailmail members only, as I recall. Anyhow, I have been using grib files from Saildocs for years and recommend Jim’s “Viewfax” viewer … I like it better than the Passage Weather display since it overlays wave and pressure data. For the stand-alone viewer (doesn’t require the installation of the Airmail program) go to and download the beta copy at the bottom of the page (currently version 5.0.035.

  2. DRWare says:

    Wow, a much better explanation of saildocs than what I posted to my blog. A lot of extras I did to know about. I am going to have to play around with the weather faxes and NOAA images. Thanks for the great write up.

  3. GPSNavX says:

    For Mac users, GPSNavX/MacENC has the ability to request GRIB files from SailDocs. It provides the user an easy interface to make the request for a GRIB file. The GRIB file is then overlaid on the marine navigation chart.
    MacWX is the Mac OS X client for the OCENS WeatherNet service. MacWX is optimized for lower speed connections such as those of cell, satellite, or HF. OCENS WeatherNet offers thousands of weather products including GRIB files.

  4. ibsailn says:

    I use Expedition ( viewing my Grib Data (and processing weather routing). At work I use the free version Expedition LT (
    The download doesn’t seem to be listed on the website text anymore, but is available for download and is also linked to and hosted by ProGrib ( as well.
    It is one of the better viewers I have played around with, able to show many layers (Surface Prssure, Wind, Current, Rain, Air Temp, Sea Temp, Sig Wave ht, Mean Wind Waves, 500MB, 1000MB, SSH deviation, & Mean Wind Wave Period) and even has a simple C-map world chart.
    It has a simple

  5. Norton Rider says:

    This is not weather related but… Is there an inexpensive (freeware/shareware?) program out there that displays currents graphically?

  6. ibsailn says:

    I assume you mean Tidal Currents. Expedition LT will display currents from a grib file, but I have only found ocean currents available this way. Full Expedition (and many other charting software) shows tidal currents as well, but is far from free.

  7. Russ says:

    Jim Corenman’s contributions to sailing and communications are broad and deep. I’ve used saildocs, Airmail and Winlink and I’ll take this opportunity to thank you!

  8. Matt S. says:

    I thought that name looked familar … I haven’t seen Gram since our days back at Webb. He came up with an ingenius way to watch movies through his computer with one of the first video input cards/tuners.
    Well nice article, even though I have yet to sail far enough for where weather routing and grib files need to be used. … After all the naval architects delmia, work in an industry you love, yet be compensated so little it takes you years (or decades if your lucky enough to design yachts) to make enough to ever own a boat.

  9. mark woodward says:

    I have assembled a Grundig YB 400PE and a Metz weatherfax antennae connecting to my PC. What is the most user friendly software I can use to download weather data. I am not very knowledgeable in this area. What does it mean that the carrier frequency is 1.9 kHz below the assigned frequency.
    Thanks for the help.

  10. fab says:

    Is ther a way to have in the same grib COAMPS wind, waves and direction and the curent of RTOFS ?
    Best regards

  11. Nick says:

    Yes – you just load all the files into the viewer.

  12. Eric says:

    You can also retrieve the OSCAR ocean current model which is generated by Earth Science Research (ESR) by using OSCAR as the leading term
    Send OSCAR:44N,40N,72W,67W
    While OSCAR is lower budget than RTOFS and NOAA’s HYCOM model, I’ve found the equatorial currents to be much more accurate than RTOFS even though you only get a 1 day snapshot compared to the many future time slices and high resolution of RTOFS.
    Also see

  13. chriggel says:

    Mark, have a look on JVCOMM32,
    It used to be the best decoding software for me.
    I am not using the PC’s soundcard anymore to decode weather fax and RTTY messages, as there is a much better and simpler solution:
    This box stores FAX/Navtex/RTTY messages 24/7 and you connect your Laptop via USB to download the messages from its memory. It has a great SDR receiver and the price is reasonable. And the best: You do not have to manually program the frequencies or forecast schedule – you just tick the boxes for the forecasts you want.

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