Hi Rinie

maybe it's because my architectural background, but i look at compositions in portions... we westerns always read from left to right, (asians vica versa i quess) wether it's a book, a photo, as well as in 'real life'... that's just how our mind works...

In an landscapeformat as you skater here, there are invisible lines on the sides (the green ones) that we call 'de Gulden Snede' (don't know the english word, 'Sectico Aurea' (lat.)) many famous painters used that as well... Da vinci but also Mondriaan became famous by using it...
When you place the main item between thoose lines your photo becomes more harmonic and static... nothing wrong with that but when you want a dynamic shot the main object has to be closer to the green lines... in that way you give the viewer the illusion that the sketer is going somewhere...

With the horizon (blue lines)it works sorta the same, but the photo becomes more interestingwhen you obviuos decided where to place it... bungling in the middle is most of the time not enough...

As i said it's only an opinion

Regards Jorrit