Nav tools mod question. Nm vs km

[Von Due]

Wondering here, are there any mods that adds navigation plotting tools (marked ruler/protractor/compass) with nautical miles markings and fractions of Nm? It would be useful when plotting intercept courses without having to convert between Nm and km.

Example:
A convoy is reported 60 km away doing 8 kts and the position and course shows an interception is doable, and you want to figure out the best intercept course. Problem is the plotting tools are all in meters and km while speed is in Nm/hour. No biggie with a calculator at hand but if you want to do it without any calculator, it becomes a bit more involving, converting from Nm to km and back.

With plotting tools showing distances in Nm, this would make it a lot easier to do on the fly using only in-game tools.

So back to the original question: Are there any such mods or would it be something for capable modders to consider?

[BigWalleye]

1 Nmi = 1.85 km. You can use 1 Nm = 2 km, with a 7% known error. Just multiply/divide by 2 in your head. A 7% error is not good enough for a fire control solution. But it's certainly good enough for approach and engagement planning. Once you reach engagement range, you can refine your fire control solution with visual/hydrophone data. No need to modify existing tools. It's the kind of shortcut RL kaleuns used.

[Von Due]

1 Nmi = 1.85 km. You can use 1 Nm = 2 km, with a 7% known error. Just multiply/divide by 2 in your head. A 7% error is not good enough for a fire control solution. But it's certainly good enough for approach and engagement planning. Once you reach engagement range, you can refine your fire control solution with visual/hydrophone data. No need to modify existing tools. It's the kind of shortcut RL kaleuns used.

Thanks for posting. I know a Nm is 1852 meters exactly but the entire point is to not having to do any calculations but do all measurements with in game tools.

[makman94]

Thanks for posting. I know a Nm is 1852 meters exactly but the entire point is to not having to do any calculations but do all measurements with in game tools.

Hello Von Due,

you can use the nav tools safely and accurate for intercept plotting porpouses. there is no need to convert nm to km or vise versa.

look at the pic:

http://i64.tinypic.com/f2n7df.jpg

at the left bottom edge of image, i have note the formula for the angle A1.
as you can see, the angle A1 depends only from the fraction u(t)/u(b) (angle θ is given).
the fraction u(t)/u(b) is not changing if you convert nms to kms

[Von Due]

Thanks, makman94.

Perhaps I failed to make it sufficiently clear but the idea is to avoid all calculations and instead rely solely on the plotting tools where the plot will reveal not just distance and heading, but also estimated time enroute. Draw the line, know own speed and and read the time directly off the plot. With say a marked ruler with Nm marked as well as 1/60th or 1/3600th of a nautical mile, one could also instantaneously figure out run distance over time for torpedos at various speed settings, again without using any form of calculation.

[makman94]

Thanks, makman94.

Perhaps I failed to make it sufficiently clear but the idea is to avoid all calculations and instead rely solely on the plotting tools where the plot will reveal not just distance and heading, but also estimated time enroute. Draw the line, know own speed and and read the time directly off the plot. With say a marked ruler with Nm marked as well as 1/60th or 1/3600th of a nautical mile, one could also instantaneously figure out run distance over time for torpedos at various speed settings, again without using any form of calculation.

but you don't have to make any calculations.
once you have found the intercept point, you can measure the distance with your ruler (in kms. ruler is measuring kms) and then you can use the rings for calculating the time you need to get there (or the torpedoes)