With 3 inspection ports, I'd be surprised if tank didn't have baffles.
Can you see any discoloration on the outside of the tanks(s) in-between the inspection ports? If there is, that may be where the baffles were welded to the interior walls.
If it was me, I'd open up the inspection ports see what the insides look like. You'll need to any way.
We had a leaking SS water tank on our last boat. We were able to remove the tank and found a few pin hole leaks along a bottom seam. We had a 1.5" by 3' piece of angle iron welded along the outside of the seam. I have been told that the leak was not a surprise on SS water tanks.