Seawolf and 688i have both a bow and stern (i.e. the towed array) sonar so you get 360 degree coverage. The towed array is more sensitive so better at picking up contacts. I did notice the towed array is not deployed in shallow water which makes sense.
I have been playing the SCS campaign with the 688i flt 2 and 3 and have no problem picking up chinese subs. They do not have a towed array so are deaf from the stern.
watch the "ambiant noise" setting in the conditions tab, that can have a huge impact on your ability to pick up contacts.
I set mine back to the original 5db per sea state from the current 3db setting. Trying to track contacts with a 110+db ambiant noise environment is a real challenge.
