Stock 1.5, I have waited for the radio message, and move into the area for Coral Sea.
The Ships rendered, I got most (possibly all) the "big fish" on the eastern side.
Couldn't find the rest on the western side.
As far as the others, I can't say.
Have had trouble with SH4 (and SH3) not rendering properly for the last several months due to driver/wine issues (I'm running Linux), so no more playing for me (for now).
I've been occupying my time with a bunch of (even) older games and Kerbal Space Program... Right now it's a heavily modded Mass Effect 2.
So I'm "out of the loop" for most things SH4 for now.
Barracuda