I use a similar rig on the kayak...but I just use a San Diego knot and a squashed down barb with a snap swivel on each end...just put the upside down hook in the fish's upper lip and send em down.
On my skiff I use an inverted milk crate with weights on each corner and 75' of rope...so much easier to just drop the small fish in the water and send them down with the crate.