I have run dual transducers from different brand fish finders on my boat before with no problems. I have heard mentioned before that you may have problems with the signals interfering with each other. I didn't experience any problems, worked great for me. As a matter of fact, I found it had had benefits over a single transducer installation. I always get nervous when running in unfamiliar waters when my depth sounder loses its bottom reading. The transducer that I used for the fish finder at the helm, I would angle at a much greater degree towards the bow. I found mounting it that way gave a much more reliable bottom reading when at cruising speed. That may throw your depth reading off a little bit, but the other transducer I mounted in the standard way so it would be more accurate.
Lots to be said for a dual system, transducers can be damaged, and fish finders always die at the worst times. I have had to replace fish finders several times while on vacation when using a single mount setup. With a dual setup, you would have to be extremely unlucky to have both die at the same time.
I don't know anything about using adapters to enable two finders on one transducer. Maybe someone else knows some info in regards to that.
Personally I would stick with the two independent systems. At least you know that you won't be out of commission if a submerged object strikes and damages your transducer.
Hope that helps a little, TheBigGuy.
