If you're looking for a powerful and waterproof Bluetooth speaker, JBL's Boombox is probably a good option for you. Many retailers are now selling it for $350, which is $150 less than its original retail price, even though it's been going for about $450 recently.
The combination of the Boombox's dual 20mm tweeters, 30W amplifier, and dual 4" Woofers means it can blast music loud enough while remaining portable. You can even pair it with other JBL speakers if you're looking for a truly immersive experience.
The device comes with a ginormous 20,000mAh battery, which should give it enough power to last for 24 hours, according to the manufacturer. You can also use it to charge external devices, thanks to its dual USB outlets. Lastly, the Boombox's IPX7 rating means it's an excellent choice for your pool parties, as it's designed to withstand rain, water spills, and even submersion.