It's OK, but why didn't they swerve to the side instead of going under the ship?
Two characters (the captain and the xo) spilled the beans very quickly with hardly any pressure. I seriously don't believe the captain would tell her about the threat from the other sub. He just wouldn't.
And it was so obvious that jade would be found dead.
And when the car goes off the road it falls into deep water. But when she comes out, it's onto a beach.
I fond the jumps between the sub and the surface jarring, but without the amount of suspense required on the sub to make it interesting.
Also, as my dh pointed out, lesbians are in everything these days. It's almost a requirement.
I think it's OK. But not more than that.