Susan Casey's The Underworld, a book about deep sea exploration, has received rave reviews, but I found myself underwhelmed. Substantively, her book contains very little information that isn't already online: this is not new information, but old material, presented newly. Unfortunately, this leads to two major shortcomings.

First, the chief value she adds to existing information is a series of in-depth interviews with people engaged in exploring and studying the deep sea. Her interviews, however, border on hagiographic - in fact, she goes out of her way to dismiss and defend some of them against serious concerns about the colonial nature of their endeavours, instead of taking these arguments seriously, as they ought to be. It feels as though she uncritically accepts and believes anything she's told: her scepticism is reserved only for a museum docent who mansplains, she says, and has nothing to do with the subject material of the book. I'm not the only one to feel this way: in the Scientific American, a review notes that "Although Casey pays lip service to Vescovo's critics, The Underworld would have benefited from a more thorough examination of ocean exploration's politics and power dynamics. In the 21st century, must our most celebrated adventurers remain impossibly rich white guys?" https://www.scientificamerican.com/article/todays-deep-sea-explorers-are-mineral... It is particularly acute when you realise that Vescovo, a rich hobbyist explorer who receives fulsome praise from Casey, is also known for doing reckless solo dives and freewheeling on safety precautions. After the Triton sub incident, and the vast amount of public funds expended on attempting to rescue the rich and reckless, can we afford to be so flippant about the subject?

Second, when you have no new research to contribute, but you write an essay, the expectation is that you write in a manner that presents the information lucidly, in a way that is engaging to the reader, and a pleasure to read. Otherwise, you're writing a high school science report. I found her writing passable at best, and often amateurish, bordering on egregious. Debris around the wreck of the Titanic is described as a "piñata of tragedy". When she's not being flippantly funny, she's buried deep in the purplest of prose, as though she had never come across an adjective or a cliche she didn't immediately want to insert in her book. Perhaps I'm being a little harsh - it's clear that she's passionate about the ocean, cares deeply about conservation, and loves the water. Still, when the quality of nature writing is set to a high bar by authors like Helen MacDonald, Robin Wall Kimmerer, or Camille Dungy, it's hard to accept this level of glib, uncritical pedestrian prose. I'm sure Booktok will enjoy it. ( )

I love finding out all the stuff we don't know yet. And the ocean is so unexplored it's mind numbing. This was clearly written just before the Titan disaster last year, so there's no commentary on that. I'm thinking the author would be sympathetic to their cause though. It's a difficult tug of war between wanting to know everything about the ocean and wanting to leave it undisturbed and alive. ( )

This book is filled with facinating facts about the deepest sites in the ocean. Casey's approach is that of a neophyte who joins adventurers and scientists as they explore these little known places on the earth. She makes compelling cases for their preservation and the need for further exploration. ( )

An exceptional book! Such an amazing world that has been for so long overlooked. Thank you, Susan Casey for sharing your adventures and insights. Ms Casey is a wonderful writer. She really captures one's attention and doesn't let go. I will be following up on her suggestions of ways to help protect the depths of the ocean. Thank you for bringing its importance and fragility to my attention in such an engaging way! ( )