In the following ship scenes, Foam particles suddenly occurs on the entire sea surface in frame 3.
(and Barth Volume will be ignored)
Using Phoenix FD 20180228 Nightlies
I’m found, When Grid cell size is slightly changed (0.22 to 0.27), whole particles do not occur.
What is the cause?
Hello,
In your scene you have the “By Free fly” option on. You can find more about it here - Chaos Docs
It is not recommended to use a value other than 0.0 for ocean simulations because the liquid might sometimes be in a temporary state of free fall and create particles all over the place.
So just set the By free Fly to 0 and reduce your Splash Threshold so it will be easier for the splashes to be born.
Also make sure that your Birth Volume geometry is set to Non-Solid from the Phoenix FD properties if you don’t want it to interact with the rest of the simulation.
hello, Georgi
In your scene you have the “By Free fly” option on.
Oops! That was right. Thank you for your advice.
solved. Thank you very much. 
Just a tip: The ship geometry should be solid (closed) without any overlapping faces, open edges, multiple edges etc. Otherwise, you could experience some strange simulation behavior.