Keep your belongings dry as you take to the water! The Loksak aLoksak is an element-proof protective bag with an abundance of various sizes available from the smallest phone-sized bags to behemoths big enough for a rifle.
Sold in 2-packs.
Resealable and reusable for many, many times. The seals will eventually wear out and it requires replacing the bag with a new one but it takes a good while.
For such a simple product, the aLoksaks have a long list of specifications that set them apart from other attempts at element-proof bags. They are made from FDA and NSA-approved medical-grade materials for food and biohazard storage and maintain touch screen capability and sound transmittance of phones and other smart devices.
The dual seal is very precise and may require getting used to. The feedback of getting a proper seal is not audible so start at either end, align the tracks carefully, and trust your fingers.