The Summerproof Speaker

Outdoor Tech Big Turtle Shell

The Outdoor Tech Big Turtle Shell speaker connects seamlessly to your phone via Bluetooth, can play loudly - up to 110 decibels - for 16 hours, and can even recharge your devices. It's water- and sand-resistant, so it will survive beer spills, roughhousing, and pop-up storms. You'll likely tire of summer before this speaker does. 
[$230; outdoortechnology.com]