At last, Frank wins…
OK, before I get bombarded with emails informing me of my acoustical error, let me acknowledge that yes, I do realise that sound does travel through water. I think from a cartooning perspective, that anything goes and at least Frank has used his boss’s lack of knowledge to his advantage for once.
In fairness to the depicted scene, sound will have difficulty in reaching Frank as it is travelling through air before it reaches the water, so there is an element of reflection and absorption that occurs when the sound waves hit the liquid.
But did you realise that sound travels fastest through a solid (about 6000 m/sec) when compared with liquid (1480 m/s) and air (332 m/s)? This is so because the molecules are packed tighter together in a solid, than a liquid or gas and allows for a more effective transmission of sound.