I was fortunate enough to watch these guys use their neat switch-and-bait techniques. They had cleverly modified the livewell to store a couple of big slimy mackerel in tubes, which not only keeps them alive but also provides quick access to the baits for the switch. They screwed two 4-inch diameter plastic tubes, long enough to hold these big mackerel, into the livewell. They wired a 1,500 gph bilge pump into the bottom of the well and ran a length of hose off the pump under the tubes to constantly circulate water through them. The system worked great, and the baits stayed alive for hours.