The idea behind this shot is a good one. I think you have a bit much forground... Empty, dull pavement is taking up half your shot. You can crop this, but as you say, the quality isn't that good. If you're not happy reshoot it! I'm sure your friends will be more than happy to go boarding with you again :) Don't be afraid to get a little closer, it will help in bringing more drama to this type of a moment. If you zoom in on this, your friend will look larger, and his trick will look larger... Try getting him when he's catching air, it will provide for a more dramatic shot. You're shooting digital, film isn't an issue