Hi skip -
There are lots of fiberglass mites (aka snapping shrimp) are well known to anyone that has spent a night in marina del rey - their incessant clicking sounds like something is outside the boat and eating through the hull. A bit of literature review determines that:
1. While not directly a weapon, submarines could escape detection by hiding out in areas where the shrimp-created noise would hide or mask the submarine. A depth charge would have an affect similat to the shrimp's snapping behavior.
2. Falling asleep to the crackly sounds of the shrimp is pleasant once you get used to them.
3. The heat produced in the collapsing cavitation bubble does approach the heat of the sun - that was surprising to learn.
4. The noise as a decibel reading is louder than a rocket launch.
5. And the whole mechanism depends upon cavitation.
Not sure about sperm whales - i have only encountered them mid-Pacific and not in southern california, so i will leave the whales out of my answer to your question.
And cruising southern california is a.lot of fun!
- rob