While pretty to look at, as others have mentioned these types of shots can become uninteresting, making it necessary to create interest with what you have. I know this probably will get criticism, but I think we often forget that the "rule of thirds" is a "rule of thumb" or guideline, not some cast in stone arrangement. Guidelines are fine but you should not get into a rut that certain elements have to fall within arbitrarily designated sets of point within the frame. Color, structure, and texture are all elements of a composition that when used with a strong central focal point like the sun can create interest, while keeping the eye firmly grounded in the frame.
In this case a polarizing filter would not have worked. A polarizing filter is only capable of its maximum effect when one's line of sight is perpendicular to the direction of the sun. In a beach scene like this with sun in front of you or behind you a polarizing filter will have no effect. Even if the sun were off to either side a polarizing filter would not have been a good choice here, because when there is a lot of color going on, such as at sunset, removing the polarizer from your lens can actually help your shot by letting that color be reflected off of any wet surfaces in the image.
Your image isn't that bad just needs some help to accentuate the positives. One filter that is handy to have around is a graduated ND filter and would have helped you get this in camera. Basically what I did to your image in Lr was adjust it to highlight the colors, and structure of the elements. Then I pulled a graduated ND filter from the top down to tree line, lowered the exposure, boosted contrast and Dehaze to clear the sky. Pulled another graduated ND from the bottom up to the trees, lowered exposure slightly, dropped the highlights, increased texture and clarity, and warmed the temperature to match the sky.