NIRVANA Waterproof Sling Pack

This 7.5 liter fully waterproof (IPX-7 rated) fly fishing sling pack with easy to use airtight zippers is large enough to carry your fishing gear for the day and probably a lunch as well. It is also small enough that you don't feel like you have a large backpack on one shoulder. It has comfortable and breathable padding for your back and shoulder so you can wear it all day. 
 
Some notable features: 
Fully waterproof and air tight.
Medium sized 7.5 liter main compartment.
Net holder slot on the face for long handled nets. 
Lots of gear clips on the bag and on the front strap. 
Comfortable padding were it's needed. 
Fits over left shoulder (great for you right handed casters). 
Gear straps to carry a fishing rod or rod tube, these straps are removable. 
Lots of side pockets in the main compartment to help organize. 
Also has a small front pocket on the face of the bag.
Easy to swing to your front to access all your gear when needed.
 
Specs for the NIRVANA Waterproof Fly Fishing Sling: 
Weight: 1.24 lbs (20 ounces)
Compartment size: 8.7" wide x 14.6" tall x 4.3" deep
7.5 Liter compartment
IPX-7 Waterproof rating