The Steamboat ZS2 sling from Umpqua carries like a fully-supported backpack leaving your line-of-sight and range-of-motion free up front. Perfect for spey and switch fishermen.  A thumb-loop allows for easy “slinging” from back to front for quick access to essentials.  A large main compartment easily holds a light rain jacket, lunch and boat box, while a secondary face pocket is great for accessory organization and smaller boxes storage.