Bill Herzog's 'Steelhead Drift Fishing' distinguishes between boondogging and side drifting. He defines boondogging as fishing at the same speed as the current behind the boat, and recommends letting the rig touch bottom only every 15-20 feet to minimize snags. The weight used is roughly double that what you'd use if fishing the same water from the bank as you're dragging the rig behind you. The Skagit is where the technique originated, according to Bill, and boondogging is most often practiced out of jet boats on big rivers.

'Side-drifting'is mostly done out of drift boat. Casts are made either downstream or straight out, and the weight used is much lighter than for boondogging. The drift is a 'standard swing' with the exception that the boat is moving so extra water is covered. The rig is presented at around 50-75% of current speed as well. This technique is recommended as the best way to cover the most water from a drift boat in a single day.

Pages 45-47 of this must-read book cover the techniques in greater detail.