I am experiencing some problems with ocean foam particles are floating on top of my ocean grid, not sticking on top of my ocean grid if I enable masking noise in ocean spectrum. Anyone have solution to this? I am currently using 18.0.532

Yeah it's weird.. A quick fix would be to displace the flat foam particles with another oceanevaluate node. So turn off “Displace Particles” on the oceanfoam and put the points in the “Geometry to Deform” input of the oceanevaluate.
The points actually won't be rendered, they will be used to drive the diffuse amount of the surface based on the position and therefore they need to be flat on the surface, which is also flat in SOPs and gets displaced on rendertime –> check “Displace Particles” under “Ocean Evaluation” https://www.sidefx.com/docs/houdini/nodes/sop/oceanfoam.html [www.sidefx.com]

So for example a custom foam sim you can still use the oceanfoam node for emitting the particles (Mode Emitter at the top) and then displacing them afterwards with a oceanevaluate