Assault generally requires recklessness or intent to injure in addition to physical contact and/or an actual injury.
Kidnapping requires an abduction in addition to intent to commit certain additional acts (human shield, terror, ransom, hostage, rape, etc.) The only way I could see a kidnapping charge in this circumstance would be if the diver being removed was a government agent on official business.
I agree that it's generally best to keep your hands to yourself, but with intent or recklessness being an element in these crimes, conviction seems doubtful. Hell, even harassment requires intent to harass annoy or alarm.

