As it stands, it feels like a chapter from a novel which has been cut off too early. This, however, is minor: it's still well-written, and if it has the feel of coming from a longer work, it's a work I'd very much like to read in its entirety.

In fact, if you are going to make something novel- or novella-sized from this, perhaps a few flashbacks or introspective moments would add to the atmosphere. I must say I love the descriptive language, esp. the "deep, cold and violent ocean"!