When the Belfast flight takes-off from Glasgow it climbs steadily reaching maximum altitude high above Alisa Craig and from there commences its descent and glide path for Belfast.
Alisa Craig is a prominent landmark for ships entering and leaving the Clyde
It is also the origin of the high quality granite used in curling stones
In the early days of lighthouses some were placed in the wrong location i.e. too high. This was the case on Ailsa Craig when the original light often became obscured by fog resulting in ships floundering so close to home