I got the pleasure of using the Chums Downriver waterproof case this summer for my weekend sup trips here in NJ. I have to say it is great! They are very high quality and give the needed extra waterproof storage for small items like your keys, wallet cell phone etc. so you are not worried about leaving them in your car.
At first I wasn’t sure about putting my $850 iphone in there so I tested it out by putting some napkins inside, blowing it up with air, sealing it closed by following the recommended instructions, and submerging it in my sink several times.
Sure enough, the paper came out as dry as it went in so I have been using them ever since! I highly recommend these cases.
You can pick one up here: https://www.chums.com/accessory-cases/storm-series-downriver
Here is some more info on them from Chums:
“Building upon the popular Downriver, the updated Downstream waterproof accessory case features a roll top closure that can be worn as a shoulder bag or waist pack while paddling, kayaking, or stand-up paddle boarding.
Its unique water-resistant exterior front pocket is made of double-sided TPU coated nylon with a drain hole for quick drying clothes. Small and compact for personal belongings, electronics and accessories, the stylish roll-up includes a one-handed quick adjust strap for easy access and maneuvering.”