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Old 05-09-2015, 16:06   #31
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Join Date: May 2007
Location: Florida
Boat: Catalina 470
Posts: 2,086
Re: Decoding the multitude of sat phone threads.

Looks like you've got things worked out fairly well...and as Evans, Don, and I said up front, an Iridium 9555 should do you well!!
And, I feel a bit stupid, cajoling you into describing your thought process and reasons...after all it matters not what I think!!

But, if you're still interested in some further input, I do have somethings to pass on that you might not be aware of...first regarding GRIB charts..
And, even if you are aware of these facts, perhaps this will help out some others...

1) Here's a fact:
GRIB files / GRIB'ed weather charts, are raw computer model data, that has not had any human input at all, let alone any professional maritime meteorologist input...
(and some/many sailors who use GRIB'ed data, unfortunately only use GRIB'ed charts from one model....and many others are still unaware that these are all raw computer model data..)

This puts GRIB charts, in direct contrast with WeFax charts (from various maritime nations worldwide) which are prepared by professional maritime meteorologists...
And, when looking at weather forecasts/charts prepared by the meteorologists from the US NWS, you'll see that they sign their name to these (so that everyone can see how good they are!)
Marine Radiofax charts

But, this is not to discount the pros from the UK, France, Germany, Aus, NZ, Japan, China, S. Africa, Russia, etc., all of whom produce professional maritime weather forecasts and charts for offshore / hi-seas water...

{Please note that you CAN also use an Iridium sat phone / data kit, to access saildocs....and from saildocs you can get wefax charts, you are NOT limited to only using GRIB files...}

2) Here's opinion:
Now, please understand that GRIB charts do fill a niche, where "1st world weather forecasting" is non-existent, not-complete, or less reliable, due to the remote locations (southern ocean, Patagonia, etc.)...and in instances where long-term reliable forecasts are not required...

Some here will tout the "accuracy" of GRIB's, and I won't enter into these arguments except to say this all depends on how many days out you're comparing and what someone's definition of "accurate" is...

Again, my opinion here, but one to two days out, in the typical cruising routes, they're fine....3 - 4 days, during the cruising seasons in/along these "Milk Run" routes, and they can still be useful, although not something to be relied on completely...
And, in/along non-typical cruising this gets complex, as some models in some of these areas are great....and some aren't...(or so I have been told 2nd hand)
But, when in those areas / of-season / etc. most cruisers will have other weather sources too...

So, the one to two days model runs will usually be fine....
But, before you decide to rely on longer-term model forecasts, you should probably get input from those out there using this raw model data in more remote locales / off-season / etc...

3) I hope you see that it isn't just that WeFax charts are transmitted worldwide, for free....but that they (as well as the Voice weather broadcasts, and the "text" weather / NAVTEX, SITOR/SafetyNet broadcasts) are all prepared by experienced, professional maritime meteorologists....
Originally Posted by DefinitelyMe View Post
I presume that the free weather info you mentioned would be via a SSB receiver with a piece of software that converts signals from the audio jack on the receiver into charts like you'd get from a weatherfax machine?

4) Yeah, Evans has a way of doing this!!!
Really gets me....he's just so....succinct!! (versus yours truly, who rambles on and on...)
Originally Posted by DefinitelyMe View Post
My original question is still absolutely relevant however, and was answered in the second post by estarzinger succinctly and perfectly, saving me more hours of trying to figure it out on my own and a considerable amount more brain ache than i have already suffered, since you will have no-doubt by now deduced that my ignorance of gadgetry is sadly appalling.

5) BTW, just an FYI....the new INMARSAT satellites are for Ka-band (20Ghz - 30Ghz) sat comm....very hi-speed data, with adjustable/switchable/steerable beams....not the L-Band (1.5Ghz) "mobile" or "handheld" sat comm devices, that we are talking about, for all practical purposes, they can be ignored for most of us here....(although those with FAT wallets, who like using VSAT's at sea, might like INMARSAT's approach....pricey, yes....but very nice!!!)
Originally Posted by DefinitelyMe View Post
What i wanted to avoid by posting the initial question as i did was a long discussion of the merits of each individual poster's nav setup. The most recent posts relating to the Go, the Iridium extreme, my link to the new Inmarsat satellite and all that jazz are not, indeed related to my original question - that has been answered, for which i am supremely grateful - rather I think it is an extension of the topic of simple satellite communication systems; simple being the operative word in the sentence!

Many thanks once again

6) And, finally.....if you're interested in seeing real-world demonstrations of real WeFax chart reception, etc...have a look at these videos!!

"Offshore Weather"

"Maritime HF Communications" ("SSB")

"HF-DSC Communications"

They're all FREE, too!!

You're quite welcome, once again!!
And, I hope this further info is helpful to you....

Fair winds...


John, KA4WJA
s/v Annie Laurie, WDB6927
MMSI# 366933110
ka4wja is online now   Reply With Quote


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