1. SKORCH 2 Pack - 20L Waterproof Backpack + 10L Dry Bag - Matching Set. Sailing, Kayaking, Beach, Paddle Board, Jetski (Click Link to Check Price on Amazon)
Editor's Rating : 9.2 out of 10
Ideal for watersports and wintersports. Sail, paddle, snowboard, ski, surf, kayak, canoe, gym.The larger bags have padded shoulder straps to give you added comfort when you do fill it with your heavier possessions

2. Essential Marine Products Premium Waterproof Backpack Dry Bag (Click Link to Check Price on Amazon)
Editor's Rating : 8.8 out of 10
Waterproof, Great for fishing, camping and huntingUltra durable material will keep water out and your items safe

3. Freegrace Top Premium Waterproof Backpack Dry Bag with Adjustable Shoulder Straps (35L Pink) (Click Link to Check Price on Amazon)
Editor's Rating : 9.4 out of 10
✔ 35L Backpack size: 17.32 x 27.16inch(1.45 Pounds/658g) . With a capacity of 35L these backpacks are big enough to hold your essentials but not so big that it is too heavy for your shoulders.✔ Soft shoulder design offers your extra comfort. The padded shoulder straps will give you added comfort when you do fill it with your heavier possessions.

4. 22L Performance Waterproof Backpack Dry Bag with Adjustable Padded Shoulder Straps, Perfect Pack for Kayak, Boating, Fishing, Camping and Hiking, Floating Drycase for Men or Women, Protects Laptop (Click Link to Check Price on Amazon)
Editor's Rating : 9.8 out of 10
100% WATERPROOF: main large 22L compartment of this backpack is water and air tight. Also protects from dust, sand, snow, dirt and mudROBUST: bag made of thick and durable material with reinforced seams and straps. A quality pack that will last for years

5. Hydronica Waterproof Backpack Wet / Dry Bag 30L 8 Gallon with Enhanced Shoulder Straps. (Black) (Click Link to Check Price on Amazon)
Editor's Rating : 9.5 out of 10
WATERPROOF - With Hydronica your valuables will not get wet. The roll top and welded seams keeps water out. Period.ENHANCED DESIGN - Our new enhanced backpack strap design is perfect for all day trips. The padded straps will rest comfortably on your shoulders.