Hi HB, just getting to this as I've been away for a few days.
I must admit, I enjoyed the original opening a little better. You know where the strengths in this chapter are (the chase sequence) and I see why you've decided to get straight to it. But I I enjoyed the sinister tranquility of the original opening upon the sea, hinting at the sense of unease. I try to imagine scenes I'm writing in a cinematic way, and for me the original opening seemed to frame the narrative a little better. And in the original you get in early a hint - just a hint - of the relationship between Orc and Cass. I think it's important to retain this.
That's not to say that some of the exposition could still go, like the chatter with the rough sailor types before they take the plunge and the bit about them needing the money. That's arguably fluff and you can justify its omission.
I feel your pain, by the way. I'm now rewriting my opening for the 8th or whatever time it is in order to get it right; pain in the bum doesn't quite cut it.
Re: Orc's name, it never bothered me when I read through the first few chapters. I liked it, and I thought the Orca reference was a nice sidestep and way of subverting people's expectations. When I first came onto Chrons and read a post about TGP I assumed it was a Tolkienesque fantasy. When I read through I was pleased at the undercutting of this. If it were me I would spin it as putting enough confidence in your readers that they'll get it. Which they will. Hell, if I can anyone can.
Hope I'm not too late to help. As I said before, I can't wait to read the rest.