You just need to broadcast a made-up word of phrase with similar tones as the whales use, without you knowing what this means to the whales. The same noise should be used every time. Whales are smart, so they will learn to associate that incoherent utterance with ships.
That would be statistically unlikely. Whales have far more safe encounters with ships than lethal ones.
Persist in using the system for a while, on as many ships as possible, and the odds will get even better as time goes on. Whales aren't dumb, they'll figure it out and probably even tell each other about it.
