This book was very entertaining. The characters have very different personalities unlike all those books where every single character is likeable. However, it is episodic and wordy which is keeping it from 5 stars in my opinion.
Edit: Nope, looking back, this book was not entertaining at all. I read it at 10 years old (and wrote this review 5 years ago) because I wanted to get into the 'classics' but, in hindsight, it wasn't the best place to start. It really just described fish the entire time, and although being very well-researched (props to Verne for that), came across as an awful lot of info-dumping. I struggled to even finish the book because by the last 70 pages I was just so tired of it. I really tried to convince myself that I liked this book because, well, it is one of the 'classics', but it definitely wasn't my cup of tea.
As for being "wordy", as I described in my past review, after some research, this is likely not all Verne's fault. English translations of his work have been prone to errors and contain even some plot-altering mistakes.
If you're looking for a thrilling, sci-fi, action-adventure novel, than this is certainly not it, but if you're interested in countless descriptions of marine plants and animals, this is the book for you.