How wartime helicopters could pressure US submarines

Would effective Japanese helicopters have stopped American submarines in the Pacific?

They would make submarine attacks harder, but effectiveness still depended on enough escorts and a consistently implemented convoy system.

World War II submarines remained surface-dependent boats whose speed and situational awareness fell sharply when forced to dive. Helicopters orbiting a convoy could spot surfaced boats, force them underwater, and break their ability to overtake shipping. Depth charges or rockets would add an attack option, though Japanese dipping sonar is less certain. The Imperial Japanese Navy had useful electronics and radar, so technical adaptation cannot be dismissed outright. Even so, helicopters would not compensate for too few escorts or failure to organize merchant traffic into consistently protected convoys.