In this talk, we will present the nature of inverse problems in ocean acoustics. We will focus on localizing a sound-transmitting source and on estimating properties related to the propagation medium. New work in our group features denoising acoustic signals for better inversion results, implementing optimal transport methods to improve the convexity of the implicit misfit minimization, and developing Machine Learning algorithms for seabed classification. We will describe open problems in the field and seek solutions.