Calculating distance from Lat and Long

[sparkythecat]

I understand that you can calculate the distance between 2 points on the globe from their Lat and Long using something called the Haversine formula. Unfortunately the last time I tackled any formula that looked a thing like this was over 40years ago and I wasn't much cop at it then.

I'd be grateful if someone clever could answer the following question.


Some friends are sailing the Atlantic.
Their current position is.
Lat: 18.2151°N Lon: 57.5121°W

How far are they from their destination which is at 17.1274° N, 61.8468° W.?

[sparkythecat]

Thanks for that.

[anonymous-user]

I remember having to work these out for a navigation exam over 20 years ago.

You have to get a mean latitude and then work out the departure.

They used to take ages to do and you could go wrong at any stage giving you one of the sucker multi choice answers, I used to always leave them till last in a test.

[Ayahuasca]

Easy with Google Earth.

[url]|https://thumbsnap.com/FlKy9mSM[/url

It’s in nautical miles so if you know their speed in knots you divide one into other and you get the number of hours to their destination. Where they are they have about 12 knots of following wind, so if they are making say 6 knots they will arrive in about 2 days from the date of your post.

If they haven’t arrived yet call the coastguard! Lol.

[sparkythecat]

They arrived at their destination in Antigua on 30th January having sailed there from Fuerteventura. Their crossing took 23 days.

[Ayahuasca]

sparkythecat said:

They arrived at their destination in Antigua on 30th January having sailed there from Fuerteventura. Their crossing took 23 days.

So two days from the date of your post, as I predicted!