Steady camera's are a must. I sometimes have unsteady hands, and if you can't keep it from moving, then you could blow a one time shot or something like that. Also depends on how busy the water is when you're filming... Also, steer clear of filming in the middle of the day during the summer. The sun will fade out all of the shots and make it look like it's overcast, stick with early to mid morning and late afternoon. Also, for tube shots, stick with the flat tubes. The ones with seats tend to bounce more in the spot where you're sitting (the seat) because it's closer to the water and it's really hard to get a steady shot from there.
Work on editing as much as you can, I don't know if you have edited stuff before, but stay away from most transitions, stick with straight cuts, flashes, fades and maybe the occasional slide, or else it just winds up appearing unprofessional. Oh and don't use too much slow-mo, it bores people. What I learned with my video is that it's better to delay release to have enough footage to fill the song than it is to try to fill in time with slow motion. Use it to make a trick stand out, but never to fill in space.
Finally, if you're selling it, make sure that you get rights to license the music, or ELSE.