Happy (almost) 2010
Is/would XM Weather be helpful for long distance races? Aside from knowing when a bad weather front is coming, I am interested in knowing how up-to-date and accurate they measure the wind. For example, if we are sitting in a dead wind area and were able to view XM on a chartplotter where the better winds might be located, that would be helpful to our tactician...no?
If XM is not the correct option, what else is available to view live wind conditions.
Define "long distance race". As in a Trans-Pac? Then yes, weather information is good to have.
Get GRIB files for you area of the race (free via SSB or Internet). The software runs on a laptop and uses the boat's polars and the forecast/predicted weather to calculate an optimum route. The software looks at the route, compares VMC for headings +/- 45 deg and sets a way point 3 hours out based on the forecast, it does this for each 3 hour period until the end of the grib file. 12 -24 hour forecasts are usually pretty good, 24-96 hours less so. If you update your weather file every 24hr and rerun the routing software you should have an optimum heading based on 3 hour course changes.
The software was developed for the Whitbread. You can set the interval between waypoints and the range of headings the software considers.
It is not very useful for races under 24 hours or so.
I also have the Sirius Marine Weather service. The service is not free, but the data it provides *is* free. The XM Master Mariner product is about the same now that the two systems have merged. Since the data is freely available I don't see a problem using it while racing. It is not "outside assistance" in the same way a weather routing service is. All the data is from the same public sources (NOAA). Even though the Sirius system is built around US coastal waters, it does do some pretty cool stuff and it works at least to 18 deg S. After a couple of hours, it has downloaded a complete data set. You can then animate the forecast and see what wind, waves, or pressure are predicted to do. Again, the short term information is better than the long term. One of the things it does is give you a marine warning pop-up window for the sector you are in if one is issued. You can also read the text of the VHF weather broadcast for any selected sector.
The satellite weather stuff would be better than nothing for coastal ocean racing, but that is not what it was meant to do. For racing there are better options available. They become more cost effective when you consider the cost of the XM hardware and a $50/month subscription. You can download your GRIB files using your cellular phone, you probably have a laptop running XP, all you need is $600 worth of software and you are good to go.
The software I run is RayTech. It is an evolution of the KiwiTech software that the RTW guys used. I think you can download a demo version for free to see what it can do. You have to buy it before it will work with instrument data. It will interface directly with a Raymarine plotter, but does not require one. It will work as a stand alone with a NMEA or SeaTalk interface. For shorter races, having laylines and target speeds updated in real time is pretty cool. As is the TWA of the next leg on a buoy course.
None of these options give you real time wind conditions. If you want to look for better breeze in real time over a mile of two of race course, you need LIDAR ... that is getting into expensive toys ...
