There's an open source project for that: https://blog.unetstack.net/Project-Sabine-Low-cost-DIY-underwater-modem-using-COTS-components-and-Unet-audio https://b

There's an open source project for that: https://blog.unetstack.net/Project-Sabine-Low-cost-DIY-underwater-modem-using-COTS-components-and-Unet-audio https://blog.unetstack.net/Project-Sabine-Low-cost-DIY-under...