I would try it the same way as cdrsubron. Try to get set up so that when the task force comes toward you, you're inside the screen. Get at least 100 feet below the thermal layer, go silent, and wait. When the lead destroyer passes over you, hope you're not detected. If you're lucky, then go to periscope depth. Line up your shot. Unload all six tubes, each torpedo in a different spot. Circle around the opposite direction your target is heading to line up the stern tubes. By the time you're lined up, you may know if you need to fire them. If you do, unload again. Crash dive as deep as you dare, then go silent and get out of there.
If you're detected before you can come up to periscope depth, go as deep as you dare, go silent and get out there.
This is also a great time to use headphones with the volume turned up.
