This is hard because I really love this topic. I have such a fascination with all things marine, especially conchology but man this book just. Didn’t do it. 
I did learn some things I didn’t know. I deepened my knowledge of shells found on the shores where I live. That’s about where my positives end. He just seemed… bored? Like he really wasn’t engaged in this book AT ALL. The final nail in the coffin for me was the bizarre guide at the end on how to kill molluscs????,,,,??? Ok???
Read Spirals of Time instead. Much more engaging, much more fun, much better written.