A photo like a drawing

Sometimes my photos turn out like a drawing. I am not quite sure how this happens but it does. I hope you like this one from the Atlantic ocean :)

Photo statistics

Camera	Sony a6000
Lense	Sony selp 18-105
Focal length	18mm
Aperture	F4
ISO	100
Exposure time	1/400
Panorama?	yes - 3 Images
Location	Atlantic Ocean / Europe
Who am I, What do I do	http://bit.ly/2tDEhpP
Download this photos?	Yes: for private use - No: for commercial use!

Please give this post some steem! <3

p.s. I do appreciate all critique - please give me your input!