NAVTEX for Pacific

[crazy goose]

I have to make a decision on the purchase of a new navtex. This year we cross the Atlantic, but next year we are going south and then project to go into the Pacific.
I have a choice between a dual band (i.e. furuno nx 300 ~ 500$) or a triband (i.e. furuno nx 700 ~ 1800$).
Channels 518 and 490 kHz cover very large areas, but apparently do not give much information when in the Pacific, where channel 4209,5 kHz seems to be required.
Question : based on experience, how do you evaluate the need for reception of the 4209,5 kHz band in the Pacific (unnecessary/recommended/indispensable)? Does the use justify the expense?

[ka4wja]

Crazy Goose,
I have some info, and a few thoughts, that might help you out....

But, first you need to remember that NAVTEX is NOT designed for, and does NOT provide weather info across oceans.....
HF radio (WeFax, text/SITOR, and/or Voice), and/or sateliite data (Inmarsat, etc.) is used/required.....

NAVTEX is designed for coastal and "near-offshore" waters, out to approx. 250 miles.....
Yes, the signals DO travel farther, but they do not broadcast weather info of High Seas areas, etc......

Remember that NAVTEX is VERY useful in the areas which it was designed for, but for large areas and long voyages (such as crossing oceans), you'll need weather data systems designed for that purpose.....such as WeFax, etc. not NAVTEX.....


1) In addition to my info, you may find posting this query on the SSCA discussion board and the OCC notice boards.....
Although, it is doubtful that you'll find too many cruisers familiar with 4209.5khz NAVTEX signals, if my info (and whatever you can get from Furuno, etc.) isn't sufficient, it's worth a try....

2) The 518khz signal is the "int'l NAVTEX" signal, which is always transmitted in English, and the 490khz and 4209.5 NAVTEX signals are the "national" signal with which weather is transmitted in their native language.......

Although there is also mention that MSI (Marine Safety Inforamtion) can also diseminated on 4209.5....and I assume that would be in English....but not sure......

{ Note that I've read NAVTEX receiver brochures that state that the 4209.5khz signal is proposed for future use in "tropical areas", but haven't found any IMO / GMDSS data to support that, nor identify what "proposed", "future" and "tropical areas" actually mean.....
However, you should be aware that I have found info (how accurate it is???) on the internet which shows there are some countries (Mexico and Brazil) are "planning" 4209.5 NAVTEX stations......but, as of now, in my opinion, it is doubtful that these signals would provide you with anything that the 518khz signal wouldn't....}

3) There are VERY few 4209.5 NAVTEX stations out there.....
According to my data, there is one in Turkey, one in Vietnam, and two in Egypt and Taiwan.......
However, ALL of these nations also have 518khz NAVTEX signals as well, and their specs of their 4209.5khz stations show the effective/useful ranges as the same......
And, unless you read Turkish, Egyptian, Vietnamese, and/or Chinese, you'd not get any real benefit from them.....

4) Also, while there may have been proposals (???) for the USCG to transmit 4209.5 NAVTEX, according to the NWS/NOAA website there is no current plans to do so.....
See www.nws.noaa.gov/om/marine/navtex.htm


5) There are many places online to find NAVTEX info (and other weather and GMDSS info).....do a google search and you can spend many hours reading....from the IMO, SOLAS, USCG, Wikipedia, etc. etc....

By far the best source for marine weather data are all of the links listed on the NWS/NOAA marine weather website.....have a look, follow those links, and you'll spend hours reading much more than you ever imagined....
www.nws.noaa.gov/om/marine/home.htm



But here's a link to a PDF station list....
http://www.beaconworld.org.uk/files/...untryorder.pdf
and the website itself is....
The Beaconworld Navtex Section - http://www.beaconworld.org.uk/navtex.htm


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


I do hope I helped you answer your own question.....
But, whatever the case....here's my opinion....

A NAVTEX receiver capable of 4209.5khz NAVTEX reception is not necessary.....

Although, if I were you, I'd be sure I had a way of receiving weather info (WeFax, Text, and/or Voice) when well offshore.....
Which is something NAVTEX isn't designed to do.....

Fair winds...

John

[Hud3]

John,

I've not used Navtex, but have read that with the proper Navtex decoding software, one can receive the signals via HF radio and download them for viewing on a computer. Any perspective on this?

I agree with your recommendation regarding WeFax, text and voice, to which I would add GRIB forecasts, downloadable via SSB from Saildocs.com.

[ka4wja]

Hud,
If you're got software that can decode SITOR-FEC, and have a decent reciever (and antenna) for 518khz....then you're home....
No other software is "needed".....

But, I cannot see many doing this.....since those that need NAVTEX weather broadcasts will find the < $500 dedicated receivers are what they'll want.....

However, if you do wish to receive NAVTEX weather, it's pretty easy....
You can read the forecasts and other data, as it's transmitted....
Transmitted continuously (on a set, sequenced schedule) on 518khz.....

Some things that you'll need to make sure of:
1) You know when your area's forecast is transmitted....
OR,
2) You leave the receiver and computer ON and receiving data, and read/record ALL the forecasts.....a VERY POWER HUNGRY approach, in my opinion.....
And,
3) That your computer/software can store these forecasts, so that you don't have "listen" live......
And,
4) You'd not have the advantage of having your receiver "filter out" all weather info for areas outside your location, and provide you with just "your" weather.......
This IS a feature of most (all ???) NAVTEX receivers, and I'm not sure what RTTY/AMTOR/SITOR software (if any) that has this feature......


I'm NOT trying to discourage you, or anybody else, from getting as much weather data/forecasts as they desire/need......
Rather, I'm just pointing out why a dedicated NAVTEX receiver (or a NAVTEX rec built-in to a WeFax unit, such as my Alden Marine FaxIV) may be a much better idea for those wanting NAVTEX weather.....

John

[crazy goose]

John,

thanks a lot for this extensive information, which clears up a few things. Indeed I have been brousing extensively, but it is not always easy to find your way in the plethora of information available.

We have on board an Iridium allowing to donwload gribfiles and text forecasts, as well as a french WeFax program MeteoFax32 which works thru shortband.

There is even an old Trimble Galaxy Inmarsat C (came with the boat I bought last year), but it is not clear if it still works. Have not been able to test it. Obviously that would give all the info via SafetyNet.

Cordially
Philippe