This was an interesting, if quite brief, look in to various aspects of the oceans. Starting with pre complex species development and exploring subjects from sea species intelligence to climate change it was definitely informative. However, as with many of the similar free books on the Audible platform, there was a little more filler than I would have wanted from such a short book. Not that the filler/ chatty sections were particularly objectionable, but seeing as it's only free because I already pay my audible subscription I wouldn't have minded a little more information. All the same, the information that was there was interesting and engaging, mostly good trivia for a dinner party or something.
I have very mixed feelings about the range of free audiobooks available on Audible, as sometimes they resemble more of a podcast while others clearly could have been full book releases but have been divided up to make them more episodic. I don't object to the podcast versions, but I do think that making them a short series in order to release the whole thing at once can affect how broad of a scope they take.
I wouldn't necessarily consider them full books worth putting on my Goodreads, but I think other people might appreciate ratings for them, so I'll keep going all the same.