Perhaps you can modify the spill-over part of the Penguin, pushing the water into a lift-tube. For instance, if you make some inscisions into the "spill plate" (I have no idea what you would call that part where the water runs off), you could form a "v" shaped "cup" at the bottom instead of a flat panel. The best way to make the plastic "formable" would be to heat it up. Don't know how you would heat it up though. Perhaps you could stand the penguin in a pot of boiling water in such a way that only the "spill plate" is contacting the water. Don't want to damage it....
Next, you can use a bore bit or a dremel tool to make a circular incision in the bottom of the cup. Then, take a lift-tube, cut off about 1 or 1-1/4 inches off (or however much you need), then you can fasten that lift-tube piece to the hole you cut in the bottom of the spill plate. That SHOULD reduce the surface agitation somewhat.
You can also redirect the spill to a different part of the tank using an elbow and the rest of the lift-tube that you cut up.
The only problems I see with this are:
1) you don't want to make a mangled mess out of your penguin, so practice shaping plastic on something else first.
2) How to affix the lift-tube to the newly formed "cup". I'm an amateur, but I bet that epoxy or rubber cement would/could poison the tank. Perhaps you can use some sort of gasket or caulk or something, i dunno...
3) How to prevent the water from spilling over the "cup" instead of into the tube. I think that you would need to make this cup big, and have a pipe or tube with a big enough diameter to handle the flow.
I also guess you can use regular plumbing pipes instead of a lift tube as well. That way, you can use a series of pipes and fixtures to start from the new cup to anywhere else you wanted.
These are just my boneheadded ideas, and I don't endorse any of them. They may work in theory, but who knows what the heck would happen if you actually tried it!!!!
Take Care,
Frank