Here is a rugged, waterproof speaker with a built-in power bank that you can take anywhere to enjoy your music. The Turtle Shell 3.0 floats on water and can be linked with other units to provide you with a richer sound experience. The power bank can charge smartphones and GoPro devices.
This speaker has buttons to control volume, pause/play track, answer calls, and turn it on/off. The companion app lets you play from your multiple speakers simultaneously. More information is available here.