Weather Information for Voyages in the Australian Region by Kenn Batt, BOM
Long before (say 6-12 months) you embark on any voyage, either coastal or oceanic, you need to obtain an idea of the average winds and weather (the climatology) that you may encounter. A broad overview...
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High Definition (HD) and Broadband Radar by Larry Brandt
The latest marine radar buzz words are “HD Radar” and “Broadband Radar,” now being advertised by reputable radar manufacturers as the latest and greatest technology. But how are they different from the...
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Small Craft Wave Danger as a Function of Wave Steepness
I found this in my notes, and then tracked it down to this link at the NOAA marine weather page, which has several topics of interest to mariners.Very roughly, periods of less than 9 seconds are waves,...
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Revisiting the Secret Sources
There has been for several years a nice way to look at marine weather from a conventional NWS presentation, which we have written up in the past in an article called "War Horses and Secret Sources." It...
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Modern Barometry and its Important Role in Marine Navigation
Talk presented at the commissioning of the World's Tallest Barometer at Portland State University on Apr 18, 2019. (Videos of the instrument. More news.)I am grateful to Tom Bennett, designer and...
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True Wind from Apparent Wind –– Revisited.
There are several ways to define the wind. For weather work at sea we care only about the true wind. This true wind is the speed and the direction of the wind relative to the fixed earth under the...
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How to Plot with Triangles
We have had several questions on the use of these lately, so here is a quick answer. It takes two of them to do the job. They look like this: Problem: Draw a line through Point A in direction 057...
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Finding Longitude from Sunset
With accurate time there are several ways to find your Lat and Lon without a sextant if you ever lose GPS data. We cover each of these in the book Emergency Navigation. In this note we do one example,...
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A Few Nuts and Bolts of Iridium SatPhone Usage
With an Iridium satphone you can make voice calls, send email, and receive weather data from anywhere in the world. Turn it on, pull out the antenna, and rotate it so it will be in the vertical...
View ArticleWeather by Satellite Phone
Weather data are available underway by satphone from commercial weather services or by conventional email request and delivery. These same data are available by HF(SSB) radio, or by Internet links on...
View ArticleEbooks Onboard
Love them now, or love them later.The value of digital publications for an offshore sailboat is pretty obvious. We can store a boat-sinking load of books on a thumb drive, available now with 128 GB...
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How to spell FitzRoy... or is it Fitzroy?
Robert FitzRoy was the Captain of the Beagle that took Darwin around the world on one of the most famous voyages ever. But beyond a famous ship captain, he later became the father of modern marine...
View ArticleNew Starpath Kindle and iBooks now online
Starpath textbooks function well in several ebook formats. They offer full color graphics, zoom for detailed images, highlight text, search and find.They offer a functional and economic alternative or...
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Mean Sea Level, Tides, and Barometers
Recently on thinking about the precise elevation of my desk for making barometer corrections, i happened to notice for the first time that a navigational light that I see every night is about at eye...
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Point Four Four per Floor––QFE to QNH to QFF
Several years ago we developed a jingle for making elevation corrections to barometer readings for quick conversions from station pressure measured at some elevation to sea level pressure needed for...
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Tides in Puget Sound
In a recent note I addressed the issue of correcting a barometer to sea level accounting for the tide height. The conclusion was that the barometer elevation to use is the height of the instrument...
View ArticleOpen Letter to the America's Cup Rules Committee
Like anyone who has seen the Louis Vuitton Cup races, I stand in awe of the technology of the AC72 yachts, and admire the skill of the sailors and designers who have learned to sail these phenomenal...
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Free or Demo eChart Viewers
Starpath has made a custom link that is easy to remember that takes you to the place you can download free echarts in either vector format (called ENC for electronic navigation chart) or in the more...
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Navigation Calculators Online
Navigation CalculatorsFor latest version and iOS install notes, see www.starpath.com/calcCelestial NavigationAltitude Correction for Air TemperatureCompass Error from Amplitudes Observed on the...
View ArticleWhy Study Celestial Navigation in the Age of GPS?
If you rely solely on GPS to cross an ocean, you will not know if you are right until the last day.With that said, the real answer to the question is: You have a good chance these days of getting by...
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