I am sure you are chuffed about the sea life you captured on video...But...these kinds of videos are really kind of boring to anyone except the person who made it. The video is also hard to watch due to some of the eratic camera movements and angles you were shooting at. The transition effect seems neat but there were times during the video when you transitioned between takes rather quickly making watching the video a bit annoying. Color balance needs work...perhaps add some more lights or filters and experiment with them to to learn how to use them effectively.
The reason why these types of videos are not that appealing to those other than the person who took the footage is that for the most part one can find professional footage all over the interwebs of similar species. This should not be taken as negative criticism unless your intent is to impress others with your footage. If you are shooting for your own satisfaction then keep shooting and work to improve the quality.
Since the moment when digital SLR cameras became affordable, it seems like every Joe Shmo now considers themself a professional photographer, they often only know how to push the button to snap the picture and have no idea about composition and such. Similarly with the advent of affordable waterproof video cameras like the go-pro there are hordes of people taking video of everything they see and are so chuffed about it they are eager to share their, by and large, unappealing footage.
From a practical standpoint, you need to work on panning and zooming more smoothly. Also, from a video composition standpoint try to get your videos to tell/suggest a story not just a capture a fish swimming...videos just capturing fish doing their thing, be it a grouper or whale, is just not very interesting, particularly in a "home video" format.
-Z