I like horror set in confined spaces and expeditions, so that part was fun. I do have a few things that pissed me off:
1.

why the actual fuck did Aidan go back for the ring?? And lie about his oxygen every dive?? Mans should not have been there.  I think I might have preferred if he died, actually.

2. A lot of coincidental things saved a lot of people a lot of times,,,
3.

I don't love the cloth explanation, but I don't really know of one that I would have liked. I was wondering if they were hallucinating during the last couple dives or something like that.

I had a fantastic first experience with Darcy Coates' writing last year, and I've been meaning to read more of her books ever since. I was fascinated by the claustrophobic vibe of the blurb of From Below with the mysterious ship wreck, the dive angle and the promise of something dark lurking within... And I have to say that this story definitely delivered for me. While a tad overlong, the ominous and claustrophobic vibe of this paranormal horror slash locked room thriller made it impossible to stop turning those pages. From Below actually uses a dual timeline structure, where we switch between the present with the dive team and 1928 on board of the SS Arcadia in the days leading up to its disappearance. I wasn't expecting the historical POV, but I understand why it was added as it gave the story so much more dept as well as adding to that ominous atmosphere. The fact that you, like the characters in both timelines, don't have a clear idea what is happening added a hint of urgency, and while certain parts did feel a bit repetitive, it wasn't enough to prevent me from wanting to know more. From Below definitely classifies as paranormal/supernatural horror, so make sure you are prepared for things to get proper creepy along the way... Especially in the second half of the story where things become more intense. Honestly, I'm not sure why the dive team even returns to the Arcadia after the second dive! I would have run away screaming instead... If you are looking for a properly frightening and tense paranormal horror read with a locked room vibe and a truly claustrophobic feel with the majority of the present timeline set 300 feet under water, From Below without doubt fits the bill. It's true that the story is a bit overlong and the pace isn't always consistent, but the plot itself is intriguing enough to keep you fully on board anyway. 

Audiobook read by Abby Craden. She's a fine reader, though sometimes her pacing took away from the story rather than added to it. But, she handled each character's personalities well and their individual moments of fear, anxiety, despair, and joy.

I've been looking for a deep sea horror that is both "deep sea" and "horror" and From Below nails it. It's atmospheric in its description of the SS Arcadia, it is the sublime underneath, making the wider ocean seem like a safe haven in comparison. Coates takes what is often thought of as a Lovecraftian subgenre (to both horror and the gothic) and deviates from the weirdist (weirdism sub-subgenre) norm. 

A tense, scary underwater exploration story. Kept me guessing until the reveal, and even then the tension never let up. The best Darcy Coates I've read yet.