This backpack is a heavy user model that requires complete waterproofing with waterproof zippers. The wide opening makes it easy to take things in and out, and the inner bag comes with a cushioned neoprene pocket that can also store a PC. The inner pocket is removable with Velcro, so you can replace it with a variety of tank inner parts (sold separately) depending on your needs. *The front pocket does not have a completely waterproof zipper, so please store items you do not want to get wet in the main pocket.