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 Slayer 03-20-2011 08:28 AM

Useful calculators

This may be old news, but I just came across this link and thought it pretty cool:

Course to Steer Calculator

Not just this one calculator, but all of them.

On a related topic, I have a Dalton E6-B Flight Computer (looks like http://www.vandeenensupport.com/projects/rs/index.html). Came with the boat. Any thoughts on using for accounting for leeway and/or drift, or computing true wind from apparent, etc?

 hellosailor 03-20-2011 01:32 PM

The "EB6" calculator from any pilot shop. That's a mechanical calculator, i.e. paper or plastic wheels on a card, that can give you a fast graphic solution, no power or internet access needed.

If there were no instructions with it, you can find them online. Weems & Plath sell a gen-you-whine nautical version, but they work the same way.

 Omatako 03-21-2011 02:55 AM

I used the calculator to calculate the CTS using 1.5 knots of current from 135 degrees Magnetic and a boat speed of 6 knots and it replied with a CTS of 10.78 degrees towards the current.

WTF!:confused:

Firstly there isn't a helmsman that ever lived that could steer to 2 decimals of a degree and secondly, if you're going to offer to calculate a CTS then why not answer with a CTS and not with the angle you need to subtract from the widget and divide by the length of you whatsit to get to where your heading should be.

I never even bothered looking at the second calculator.

Sorry, not picking on anybody but geez . . . . .

Am I right in thinking that it thinks in term of the direction the current is coming from, rather than the direction the current is flowing to (i.e. the conventional way)?

 Melrna 03-22-2011 07:31 AM

What these calculators don't account for is the polars of a boat's velocity. Now that would be a great calculator in determining how to get from point A to B.

 Boasun 03-22-2011 08:10 AM

With my book "Formulae for the Mariner." I use a Casio fx-300ms caculator.
this is a wonderful book has just about all of your useful formulae in it. And note pages for other formulae you may want to add.
IMO, I find that it works better than any on line caculator.

Melrna: that would be great, but how would you input the polars? It's not like you could easily type them into a little box on the web page. As it is, the calculators don't take wind into account at all. But it sounds like an interesting challenge nonetheless.

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