Courtown
I think its important to have the horizon level in a landscape painting. I will always draw this important line first before the sketch is started. On bigger paintings I will measure the distance to be absolutely sure its correct.
Its not so noticeable on standard landscape because of distant hills or mountains but when the flat line of the sea is included in a painting its critical its completely level. Its all about the illusion of reality I continuously try and achieve.
I have a steel ruler I use to help me in this endeavour. By lying it flat on the surface of the painting and using it like a stencil to brush flat the lowest sky colours I get a final paint layer completely straight and level. Its amazing how crooked this line can be when painted by hand alone. Only when the ruler is employed can you see how wobbly this horizon line can be. If the ruler causes a few smudges on the lower part, usually the sea, that’s OK as these are going to be overpainted later on.
Here is the video of the painting. See you soon.
PictureS 
Awesome video! How long did this take you to paint? Looks fab 😀
I’m an oil painter, but haven’t ever painted landscapes, I tend to paint animals 🙂 Tempted to make a time lapse video myself, there’s something really cool about watching something like that come together so fast!
Thank you Natasha. This painting took me longer than it should, nearly 4 hours. Its the empty spaces, they irritate me into adding something and I just keep adding layers. Many are just covered over. I am always trying to control this overworking. You should try and produce a time lapse video. It will teach you a lot about your own working method.
Wow. Amazing to watch this emerge. The decisions made, colour use and composition is masterly. Thank you for sharing this Liam.