Maringret’s Weatherfax Page

When we set out in the summer of 2000 for the Baltic we expected to receive most of our weather information by Navtex and additionally from local sources. A summer in the Baltic soon showed us the holes in our plan. Prior to departing we had purchased a commercial Navtex receiver yet were often unable to receive any Navtex transmissions once in the Baltic. We learned from other cruisers who were using computer based systems that they had better reception as their aerials were usually the length of the backstay where as we were limited to the antenna supplied with our commercial unit. We also found out that the Navtex broadcast system in the Baltic is not targeted towards recreational craft and so is almost as inappropriate as possible for yachting (e.g. the transmissions of the 0600 weather information is usually sent out towards mid-day which means that any day tripping yacht is already halfway between harbours). Additionally we found out that transmission are not sent on all days which was confirmed by other boats using computer based reception equipment. Passing through the Balticum we were often unable to get local weather predictions, or at least unable to get them in time for an early morning departure. We realized that for more remote regions we would have to become more independent from Navtex. Other cruising yachts we met of various flags depended on either proprietary (i.e. pay as you sail) weather forecasting systems or weatherfax.

During the winter season we researched the topic on the internet and cornered everyone we could on the subject of weatherfax. The common consensus was that a simple Windows computer with certain pieces of software and hardware was all that was necessary to receive and store weatherfaxes. We looked into the costs associated with purchasing a dedicated Windows computer for weatherfax but decided that as all our other processing was on Macintosh we may as well remain with that platform provided we could locate reasonable weatherfax software, evaluated on price and performance.

Two boats we met during the summer of 2000 used commercial units. They were suitably impressed with their reception quality and we checked these out on the internet but the prices we found were well beyond our means.

As Maringret uses a Macintosh computer for her processing, we returned to look into the possibility of using the hardware we had already onboard to receive the weatherfaxes. We found the number of weatherfax packages for the Macintosh limited. Although there may be more, we found:

MultiMode by Black Cat Systems


As our mast was unstepped during the winter and the boat emptied and shut up, we first got the system going ashore. We had a Sony 7600D shortwave receiver which we had purchased in 1984. It still runs well and the number of air miles, meters vertical climbing and land miles would be scary to calculate. One advantage of the Macintosh is that no modem is needed as the audio output from the shortwave radio may be fed directly into the microphone input of the computer. We had to buy 1 meter of double conductor wire to connect the radio to the computer, 15 meters of single conductor wire to act as an antenna and 3 earphone jacks. This lead us to being able to receive the following as our second weatherfax:

one of our early receptions, the Greenland Ice Chart

Being able to play around with the setup in the warmth of your home (not to mention how stable it is compared to a rocking boat) allowed us to spend a week of evenings tuning the system and getting to know the software. We used the German broadcasts from Hamburg to get our setup going and found out that with about 8 faxes being sent each evening, you soon have more information at your fingertips than you can manage. Weatherfax reception is susceptible to atmospheric static which will degrade the image. Learning how to deal with this and store the images received requires some attention. We were lucky that Adobe PhotoShop had been bundled with our Adobe PageMill we use to maintain our website. There are more special effects and transformations in PhotoShop than we can possibly master. These all help to make a marginal image comprehensible when viewed by eye.

Another learning curve is that associated with understanding the frequencies and how they are listed. We still have not fully understood how they are listed and have basically made notes of when we found transmissions on what frequencies once the published data told us what frequencies to monitor and roughly when to look.

click here for weatherfax links

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