Sight Calc

You put in the LHA, plus the AP Lat or DR Lat, and the declination, and out pops azimuth, true azimuth, and Hc. Couldn’t be easier to learn and use and is a great time saver. You can also input a meridian angle eastward instead of the LHA by inputting it as a negative LHA. I find that calculating a meridian angle eastward is more intuitive for rising bodies than LHA so this saves me the step of converting it into a LHA. If you understand how celestial works it will also give you great circle initial course and distances just as easily. Just substitue the difference in longitude for the LHA and the Lat of your arrival for dec. I have not yet tried using it to pre-calculate altitudes for planning sights but I’m sure it would be handy for that too. Five stars for simple easy and very useful!

This app is a "must" for quick and accurate solutions to the "law of cosines" ANEO

Slide rules and scientific calculators are not my thing. Many thanks to sight Calc for getting me through the USPS JN course!

I used this a lot to get through my Jr Navigation course last year with The United States Power Squadron. It was a tremendous work saver.

Started using this apt last year when taking USPS "JN" to check my Law of Cosigns calculator method with the old ISO and it worked with some bugs. Upgraded to the new IOS 10 and had to workaround to get the answer. New Sight Calc 1.2 update takes care of that workaround using the new IOS 10. Stilling using it in my new class USPS "N" to recheck my LOC calculations...

App fails at entry of minutes in Dec line when running iOS 10. Hope they will fix!

This is a great App for doing sight reductions using the law of cosines. I would give it a five star rating except it has compatibility issues with iOS 10.

I love this App! It looks like it has been out for a while and had a lot of good reviews. I'm only putting this as a 2-star review at this time to bring attention to the fact that using this App when you are lost at sea may get you lost even further! From my testing the result Hc and Z is spot on! But will the sailors using an app like this know the difference between Z and Zn? If you assume that the result Z value is your azimuth and graph your sight based on that value, you are going to be lost at sea. Another correction is required to determine the azimuth. You have all of the inputs to make this correction, why not provide the azimuth output? As documented in the Ho229 tables: Latitude SAME Name As Declination - N. Lat, LHA < 180 .... Zn (azimuth) = 360-Z Latitude CONTRARY Name to Declination - S. Lat, LHA < 180 .... Zn (azimuth) = 180+Z The app is very easy to use and does the basic calculations correctly. Please calculate and output the azimuth and I will gladly update this to a 5 star review!

Simple, straightforward, works well. I use it to check sight reductions done with HO 249; it’s comforting to have an app give the same result as table lookups. Thanks.

Great app for sight reductions. Users might also want to check out time and degree app at App Store. This sure beats using a calculator from the last century.