I am developing an application to calculate navigation data from Sun & Star
sights (interesting for sailors, boring for everyone else).

The problem is that I appear to be getting small inaccuracies when
calculating angles. I have used Double as the data type. Looking through
the help files I note that there should be a 'Decimal' data type that uses
many more digits so potentially improving accuracy. However, a line such
as:

Dim dLat as Decimal

results in a message: 'Compile error: Expected: New or type name'

I understand that this is saying it doesn't recognise the Decimal data type.
Do I have to add a library to use this? if so which one?

Any ideas gratefully received.

Peter Morris