Guidance wanted

[Frosty3d]

I'm creating a large scale ocean scene with a submarine. The submarine is close to the surface allowing it's periscope mast to come out of the water, but the submarine is still submerged.
I've successfully created a Hybrido domain which shows the large wake made by the submarine just under the surface.
My problem is that to get any interaction with the periscope I need to lower my hybrid cell size to the point where it is taking hours to create one frame.
I would like to leave my large scale hybrido domain alone as the result of that is great.
Should I now create a small domain that will just take the periscope by itself and allow me to use a much lower cell size?
How would I combine these? If I mesh the large scale domain can I then lay the fine detail periscope domain particles on top of that mesh so it receives the large wake displacement underneath?
I'm going to be rendering in Maya.