Re: is it true
All of your examples are fine, meobeo, but they don't make the original sentence any more correct.
"Right on the coast" as ems suggested or "directly/right next to the sea" would be okay, but you're not "in" the coast, and you can't be "in the very coast" either.
(You could say "this is the very beach we came to before" to mean the same one as before, though.)
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.