Digital Art Experiment - Beach

Per my agent's advice, I am trying to transition my artwork to digital, so that I can offer client both traditional and digital options for my work. I've been experimenting for a while, and finally have something that I feel is worth showing. I don't feel my digital artwork is quite at the same level of professionalism as my traditional work, but I would love to get some critiques and feedback. If you are a digital illustrator, I would especially like your advice on technique. Thanks all!