GearBest offers the Gocomma 20-Liter Waterproof Kayaking Dry Sack in Yellow or Blue for $18.12. Coupon code "GBGOCOWPB20" cuts it to $15.99. With free shipping, that's $2 off list and the lowest price we could find. It features roll-top closure and comes with a 6" phone pouch. Deal ends August 12.

Note: This item ships from China and may take 4 to 6 weeks to arrive.