The moment a drone submerges, the standard rules of wireless communication cease to exist. Traditional radio and Wi-Fi signals are almost instantly absorbed by saltwater, leaving Autonomous Underwater Vehicles (AUVs) completely deaf and blind in the abyss. To coordinate deep-sea mapping or pipeline inspections, marine robotics must rely on the slow, distorting medium of sound. Acoustic modems translate digital commands into complex chirps and pings, but pushing data through a fluid environment is a logistical nightmare. The speed of sound underwater is not constant; it drastically bends and refracts based on shifting temperatures, salinity levels, and pressure zones known as thermoclines. A signal fired straight ahead might curve sharply toward the surface or bounce erratically off the seabed. Engineers must program subsea drones with advanced fluid dynamic algorithms to predict these acoustic distortions and successfully decipher the echoing, delayed telemetry. Tune into the frequencies of the deep. Decipher the severe physical limitations of underwater wireless communication and the acoustic engineering required to command robotics in the dark.