only one you need
If you are learning to paint the sea, or want to get better any of his books are just the ticket. Clearly written, non cookie cutter style, he gives all the basics, and more. All the while encouraging you to learn from painting out doors and other artists, to go your own way. He gives you a great plan, and when I went to the sea to paint I managed the first time out quite well, because his books gave me a logical way to start and told me what to look for. Doing his exercises also increased my skills right away. You can follow his plan and still keep your own style of painting. You can tell he spent a lifetime observing the sea and painting it for sheer love.