Tuesday, August 23, 2011

Bowditch On Disk

Every boater who has ever run up against a navigational problem to which there is a not a clear answer or whoever wanted to settle a yacht club bar bet has at one time or another looked to Bowditch's American Practical Navigator for the definitive answer. The problem with Bowditch and other tomes on navigation is that sometimes finding the answer can be as frustrating as the problem itself.

The easy way to settle these disputes is on a new CD-ROM from Starpath. Bowditch Plus contains the complete text of Bowditch's The American Practical Navigator, in searchable form, on one CD.

I was helping a friend pick out a radar for his boat and he wanted to know how far away he would be able to see objects. He thought since he was considering a thirty-six mile radar he would be able to see larger objects that far away. I explained to him that it was not just the power of the radar but the height at which it was mounted. The formula for finding the distance to the visible horizon is Distance = 1.17 times the square root of the height of the object (the radar or your eye.) (There is a slight difference between radar horizons and visible horizons, but for most purposes, the amount is negligible.)

We went to the Piloting Tables on the CD-ROM, picked Distance of the Horizon, plugged in the height of the radar antenna (25'), and it calculated that under optimal conditions, the radar would reach out to a usable distance of 5.845 statute miles. My friend is now looking a way to raise the height of the radar dome to get a better view. Unlike the book version, this CD actually computes the distance for you, not only saving time, but also eliminating errors due to mathematical mistakes.

Also included on the CD are all the chart symbols, definitions and abbreviations, US and International, indexed by name and graphical design along with all contact and internet links to all the hydrographic offices worldwide. The whole database is searchable. I looked up the Rule for the proper lights to display if you are aground and the program took me directly to the page with rule and the illustration. The complete Navigation Rules, Rules of the Road, are also included. This is a great reference tool.

You can search for terms and symbols, or you can use the convenient indexes to locate what you need. With more and more boats carrying computers onboard, this a reference tool that will help you find what you need in a hurry. The contents can be run from the CD or loaded on the hard disk. If you have the room, load the Rules of the Road and other modules you think you will, need to your hard disk. This gives you quicker access times and smoother operation.

Boats have limited storage space and this CD removes the need to carry a big reference volume with you. It is easy to use and is great example of technology making a complex subject easier to understand.

Bartender, give my buddy my tab.

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