GRIB files - what are they?
With the vast amount of information now available from weather satellites, the World Meteorological Organisation set a standard to allow such information to be gridded and referenced to latitude and longitude. Until recently analysis of this information was a very expensive business and the compiled information was only available to heavily sponsored ocean racers with huge budgets. But almost without noticing, this information is now accessible through the Internet at minimal or even no cost.

Cruising World MagazineGRIB files (GRIdded Binary files) provide a standard format in which weather data can be archived and exchanged. A range of meteorological information, including wind, pressure, temperature – even wave heights – can be downloaded from satellites and buoys. By extrapolating a series of readings taken over a period of time, the data can be used to produce forecasts for up to seven days ahead. Although earlier suppliers of GRIB data used professional forecasters to interpret the data manually, systems have now reached a stage where, once established, the software is entirely automatic. “Other companies used to use forecasters,” says Clive Hepper of MovingWeather.com. “But this involved an enormous cost which made it uneconomic for the end user. At Moving Weather we use our own software and a very high level of skill to sift the data and get it down to a manageable size.”

Although the GRIB information itself has achieved a high degree of standardisation, the format in which the resultant information is displayed varies widely from a very simple superimposition over geographical outlines, to integration into complete charting systems. Euronav, one the earliest entrants into computerised charting, introduced a facility to handle weather information into their SeaPro programme in 2001. Their system, in common with others, including Raymarine’s Raytech charting software, then takes the information a stage further allowing it to calculate routeing suggestions of considerable sophistication. The user first enters what is effectively the boat’s polar speed diagram – a record of boat speed at different points of sailing in different strength winds. From the forecast calculated from the GRIB files, the software can work out the likely wind strength and direction to be encountered, calculate the theoretical boat velocity which results, and then work out which route is likely to offer the fastest passage.
Although Euronav doesn’t produced their own GRIB files, both they and Moving Weather claim a high level of accuracy from the forecasts. But the two are fundamentally different. Clive Hepper explains that their own system is a stand-alone, dedicated weather provider. It does not offer route planning and is not reliant on expensive charting systems. For just £59 they will provide unlimited downloads for 12 months (15 months if purchased at the Boat Show). A new product that they’re also launching at London is a GPRS connection for an on-board laptop. Instead of using a standard mobile phone, they’re offering a PCMCI card (that’s the one that goes into the slot in the side) using its own pre-paid SIM card which will allow up to 1megabyte of downloads per month, with a typical GRIB download of 7kb. Moving Weather also offer an amplifier which will double the range of a mobile, making few places in the Mediterranean out of reach.

Euronav’s standard charting software starts at £450.00 which includes a simple route planning system , although a performance sailing module is available for a further £200.00. Charts start at £100.00 for a complete UK and Eire waters pack.
www.MovingWeather.com; Tel:0870 8610032
www.euronav.com; Tel: 02392 373855

International roaming
Cruising World MagazineMany people will never forget the shock of their first bill after using their mobile for international roaming. Subscribers not only pay for the international cost of incoming calls, but they can also pay for three international calls if they don’t turn off their voice mail before leaving home. The EU has recently announced an investigation into the high cost and comparisons can be seen on their website www.europa.eu.int/information_society. Many cruising people recommend buying SIM cards locally, with the main advantage being that the caller carries all the charges for the incoming call, but such a purchase can often be a cumbersome and time-consuming procedure.

GYM Yacht mobile is offering a new pre-pay SIM card which they claim is ideal for international roaming. Registered in Lichestein, there is no tax to pay and no recurring charges. In most countries their standard charge for both local and international calls is Euro 0.39 and incoming calls are charged to the caller. They also provide free voicemail and message recovery is charges at the same rate.

For Mederrranean boaters, another product of interest is Moving Weather’s mobile amplifier. Details of this company’s weather products can be seen opposite, but the recently-launched amplifier doubles the signal of mobile signals, which can mean that most Mediterranean passages can remain mostly within range.

Tek-Dek takes on teak

The sparkling teak decks admired by the new owner at a boat show soon become a distant memory. The bright planking quickly fades to a dull grey and within a few years can even start to shrink. In hot climates they become too hot to walk on, and there’s always the lingering knowledge that the whole deck might need replacing within 10 to 15 years.

When so much of a modern boat is made using synthetic materials, which should decking be any different? After all, on a GRP boat it’s not as though it still performs any practical function since it’s laid over the fibreglass, rather than being a structural element laid over wooden supports.
Tek-Dek introduced a man-made alternative several years ago, but has recently upgraded its flexible composite to become almost indistinguishable from the real thing. It is impervious to seawater, sun and is impressively non-slip. It is also a fraction of the cost of real teak with no environmental effects. Tek-Dek has now launched its new “Professional” range which is aimed at the boat builder, and has carried out a number of trial installations. Will teak decks on a production boat go the same way as wooden hulls?
www.tek-dek.co.uk

Wireless instruments
Cruising World MagazineTacktick has been producing collar-powered wireless instruments for nearly a decade now, but somehow it’s taken that long before their advantages have come to a wider market. Imagine replacing your masthead anemometer without having to replacing the wiring. The Tacktick wind transmitter needs no connections and has its own built-in solar panel.

Launching at the Boat Show is the new Micronet remote unit which can display all a boat’s functions in a choice of format. A new wireless NMEA interface can transmit data e even if the boats central systems are by another manufacturer. Apart from the ease of installations and no requirement for batteries, the units leave the factory completely sealed , to offer exceptional reliability.
www.tacktick.com; Tel: 02392 453351