Overall, 'Flood' is a fascinating novel about what would happen to people, and to civilization itself if a massive worldwide flood were to occur. This is a work of science fiction, but several of the ideas which are presented are grounded in scientific theory (the idea of subterranean oceans for example) which Baxter describes in the Afterword, even citing further reading for those interested by the concepts presented. Is everything completely believable? No. That is not, usually at least, what I'm personally looking for in science fiction though.
When it comes to the plot itself, this is where I had the first of my problems with the novel (which prevented me from giving this novel a full 5 stars). The problem I had were the gaps: my mass market paperback was 480 pages and covered 36 years (!).
Yeah, this to me presented a few problems...sometimes the action seemed to take place during what was unwritten--it was sometimes hard to care (particularly near the end of the novel) about what was happening to the characters, or the Earth for that matter, as it occurred so very quickly at times. This meant that some of the ramifications or fallout of events were glossed over, and we would catch up with the characters months after what we had just read, making it seem less important.
Character wise, I had few problems with the novel. Some of them were not as fully developed as they could have been, and I ended up caring less about some characters because we just didn't spend that much time with them. The main characters were for the most part believable and interesting, but again, were hurt by gaps in the timeline--> this novel really could have benefited from being longer (something I almost never feel when it comes to science fiction).
I suppose I should mention Dr. Wayne's review and its' mention of pedophilia--as far as I'm concerned, it's not prevalent in the novel, and what little mention of pedophilia there is, only appears terrible if you completely take it out of context. I suppose if the very concept disgusts you to the point that you couldn't read a book that has mention of it, about 10 pages of Flood could bother you...but I personally had no problems.
All in all, this is a quick and entertaining read, which I thoroughly enjoyed...but I would have liked to spend more time with the main characters.