I used this pack in the Bahamas for the last two years. What is not mentioned in the Mustad description is the zippered closure at the very top. If I am not storing this in an open boat I just zip and unzip as needed to quickly access my gear. It is a perfect size for a carry-on bag and holds a lot of gear. And it is $60.
Mustad's Dry Backpack is a practical, waterproof roll top backpack with plenty of room for clothing, camera, mobile, navigator and all the fishing gear you need for a daytrip. This durable backpack features a water-resistant outside zipper, comfortable padded straps, 500 Denier Tarpaulin material, sealed seams, mesh bottle pocket, click lock strap closure, easy-adjust padded shoulder straps and practical one-handed carry handle. Best new product award winner at European Fishing Tackle Trade Exhibition 2017!