Many movies and television series claim to push the boundaries. This one really does. As the material about the making of the series (at the end of each episode and online) shows, the four years it took to make included a record depth for a manned submersible dive in Antarctica, round the clock diving to make sure they did not miss a once-a-year event at a remote island, coping with huge sharks attacking the crew's submarine, deploying a range of novel filming technologies, and taking so much time under water that they were able to record behaviours never seen before. Around a thousand hours of shooting were needed for each hour of programme.
The results are genuinely sublime, with an astonishing range of natural wonders captured by photography that is surely peerless in its beauty, range and consistency. Skilful editing and commentary helps bring each of the subjects to life. Evocative music and sound effects may irritate some but for me, and I expect most others, these add to the impact. The conservation message is there in part in most episodes, emerging into its own in the final episode, but really the whole series is a uniquely powerful plea for the conservation of the oceans.
Beyond that there is not much to say except "see it".
Beyond that there is not much to say except "see it".