This paper presents a proposal for a new chaotic-based underwater acoustic modulation scheme. The proposed method is a differential chaotic shift keying modulation based on the Lorenz attractor. Unlike conventional techniques that use Chirp signals, synchronization is achieved using a chaotic signal. In the demodulator, a Doppler shift compensator is also implemented, capable of compensating shifts up to 10 m/s. This compensator is based on bank of Doppler shifts. In order to see the influence of underwater acoustic channel on the proposed acoustic signal, the simulations are performed. The channel was modeled by adding white Gaussian noise with a signal-to-noise ratio (SNR) ranging from -5 dB to 20 dB, multipath propagation with 7 received waves, and the Doppler effect with a speed of ±10 m/s.