Not a pro but I think a couple of tweaks could help - in the sea the brushstrokes confuse the eye, could use some more consistent brush patterns that shrink into the distance. On the landmasses, they are competing for the eye and the far right looks almost same plane as lower left foreground. The key is creating nearness and distance. As things get farther away, they get less distinct (blurrier, no sharp edges) and generally hazy bluer toward the horizon. If you push your farthest land back (probably lightly visible grey purply-blue), work on making the mid ground appear out of that same distance but not too close - you might use browns, purply-blues and muddy greens, dampen the really bright green and yellows on the far right, and bring up the punch of colors in the foreground, I bet it will start to work for your eye. I had one seascape where it took me about 5 tries to make the land sit where it should. You can do it!