Realism in Dangerous Waters.

[Dr.Sid]

That should only be possible for sphere array. Towed array only measures angle from array axis. The beam on towed array defines cone on which surface the target lies.
Due to mirror effect you can't tell if the target is 20 degrees left of the axis or 20 degrees right. But it may also be 20 degrees down and the results would still be the same.
This should be no big problem anyway. You have towed array for distant targets, and those will be very close to 0 elevation. For closer targets you have sphere array and that can show elevation.
I've seen some pictures of current sonar suites and they even used 4 waterfalls each for specific elevation range. I've heard they are called DE-EL plots - depression elevation plot. One waterfall was for let's sat +5 to +30, then one for +5 to -5, next of -5 to -15, last for -15 to -30.
But you could also get specific elevation for every broadband/narrow band contact.
Anyway, submarines are mostly 2D problem. You detect targets at 10miles, sometimes at 100 miles. If something is 3 miles, it's considered VERY close. But you can't go deeper than mile .. most subs not even a half of that. Most torpedoes on the other hand can go to any depth submarines can go. So depth really has little effect.