Bluetooth speakers can get fairly pricey, especially ones built for outdoor usage. Anker's Soundcore 2 is an exception, with high-quality 12W speakers in an IPX5-protected casing. Now you can get it for $29.99 from Amazon, a $10 reduction from the usual price.
The Soundcore 2 has gone on sale a few times in the past, but this is the lowest price it has ever been (last time it was $31.99). In addition to water and dust protection, the speaker has a 5,200mAh battery, which Anker says should last for 24 hours of music playback. It's fairly light too, at just 12.6 ounces.
You can buy the Soundcore 2 in a variety of colors at the source link below. Personally, the red one is my favorite.