The Frontier Below by Jeff Maynard

https://thebookvoice.com/podcasts/2/audible/62372 to listen full audiobooks. Title: The Frontier Below Author: Jeff Maynard Narrator: Adam Fitzgerald Format: mp3 Length: 10 hrs and 9 mins Release date: 04-13-23 Ratings: 5 out of 5 stars, 1 rating Genres: Outdoors & Nature Publisher's Summary: We do not see the ocean when we look at the water that blankets more than two thirds of our planet. We only see the entrance to it. Beyond that entrance is a world hostile to humans, yet critical to our survival. The first divers to enter that world held their breath and splashed beneath the surface, often clutching rocks to pull them down. Over centuries, they invented wooden diving bells, clumsy diving suits, and unwieldy contraptions in attempts to go deeper and stay longer.