Well, 'Leviathan Wakes' has elements of horror in the deep space setting, but it also has a lot of the same sense of the unknown and danger that you might find in 'Ocean Grave'. The vastness of space in this novel can be compared to the depth of the sea in yours, and both evoke a feeling of unease.
One similar novel could be 'The Deep' which also delves into the terrors lurking in the deep sea. It has a great atmosphere of mystery and horror.
The unique setting of the deep sea makes it stand out. It's a place full of mystery and things we don't fully understand, so it's easy to create a sense of horror there.
One similar novel could be 'The Terror' by Dan Simmons. It's set in the Arctic but has that same sense of dread and horror at the mercy of the elements and unknown terrors. Another might be 'Jaws' by Peter Benchley, which is centered around a man - eating shark in the sea, creating intense horror.
Well, there's 'The Trench' which is about a group of people exploring a deep - sea trench and all the horrors they encounter. It's full of suspense as they deal with unearthly creatures and the extreme pressure of the deep sea. Additionally, 'The Sea of Monsters' in the Percy Jackson series has some moments of deep - sea horror, especially when they face the sea monsters that lurk in the dark depths.
Well, 'The Raft' by Stephen King also has some elements related to the horror of the sea. Although it's not entirely focused on the deep sea, the sense of isolation and the threat from the unknown in the water is very much in line with the horror of the drowning deep sea concept.
One possible 'deep sea horror sister novel' could be 'The Deep' by Alma Katsu. It has elements of horror set in the deep sea context. Another might be 'Into the Drowning Deep' by Mira Grant which features terrifying sea creatures and a sense of dread related to the ocean depths.
There are stories of divers who claim to have seen strange, gigantic shapes moving in the deep sea. They couldn't quite make out what it was, but it was huge and seemed to be coming towards them. As they quickly ascended, they could still feel a sense of dread, not knowing if that unknown thing was following them. The deep sea is so vast and unexplored that there could be all kinds of unknown and scary creatures lurking down there.
One well - known bright shark deep - sea horror novel is 'The Shallows'. It tells a thrilling story of a surfer trapped in the ocean with a great white shark. The sense of isolation and the constant threat from the shark make it a real page - turner.
One horror story is about a fisherman who hooked something huge in the deep sea. As he was reeling it in, his boat started to shake violently. Suddenly, a massive, unidentifiable creature briefly surfaced, its eyes glowing in the dark. Then it dragged the boat for miles before the line snapped.
Isolation plays a big part. When characters in these novels are in the deep sea, they are often cut off from the rest of the world. There's no easy escape. For example, in a submarine or a deep - sea research station. They're surrounded by miles of water, and any help is far away. Also, the power of the ocean itself. The crushing pressure, the cold, and the vastness can all be used to create a sense of horror. If something goes wrong, like a hull breach, it's almost certain death. And the idea that there could be ancient, malevolent forces lurking down there, just waiting to be disturbed, adds to the terror.