The Nautical Almanac

You don't have an ocean horizon?

Make an Artificial Horizon




This Artificial Horizon was made from plastic boards and window glass.

The window glass is set on a 45 degree angle and is used to protect the the water filled lid from the wind disturbing the water.  The window glass that forms "the tent" is removeable for cleaning.

The black "disk" is a lid from a coffee jar.  It's filled with water to create the reflective surface.  You can use any liquid and even old motor oil.

The Artificial Horizon you see here is perfect for taking Sun, Planet and star sights.  A good dark sky is necessary for making star sights.

You can make an Artificial Horizon even using a dish of water...or a puddle.  But, any wind will disturb the water making sights difficult.

Give it a try- put a dish of water on a window sill and take a Sun sight.

When performing the sight reduction make sure to divide the Hs in half and also account for shooting the Upper Limb or Lower Limb of the Sun.



It was a cloudy day when this picture was taken.