Hi gdc3man,
There is no node with bubbles for the ships,its a texture that creates the sinking bubbles, I modified the texture to create the illusion of more bubbles for ROW and PE, the texture is inside the data/textures/tnormal/tex and is called something with bubbles
The submarines have a particle generator attached to them, which is responsible for the bubbles when the submarine is submerged.
I think it would be possible to attach a particle generator on the ships, but then you will have to learn how the particle generator work and make the particles start when the ship is sinking, it would require alot of work, because after you have made one working particle generator you would have to import it into all the DAT's of the ships.