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In the early ’90s I captained Hubert Lauffs’ 54 Bertram Colleen. Back then there was a really fun and super competitive marlin tournament circuit in Southern California, and as soon as those were over, most of the boats would depart for the black and blue marlin tournaments in Mexico. The competition was pretty fierce in that circuit, with tournaments having more than 100 entrants and everyone always looking for an edge.
I remember running Colleen down the bay in Newport Beach one day and seeing a tail sticking out of a tube on the back of Lance Alworth’s boat 19’s Toy. As the tail beat rhythmically, water splashed out from the tube. My friend Mike “Beak” Hurt fished on that boat, so I gave him a call to get the scoop. Bart Miller had showed it to Beak when he was over in Hawaii fishing the HIBT, and then he brought it back to SoCal.
Within a week we had built our own stack of tubes that fit in the transom tank. We didn’t want anyone to see them, so we strategically placed them at approximately a 60-degree angle within the tank so the lid could stay on. We already had swimming pool pumps installed for the large volume of water we needed for our cockpit and bow mackerel tanks. Since the cockpit tank had already been removed and the fighting chair went on in its place, it was an easy adjustment. We had no idea how much water was going to be needed, so we equipped each tube with its own valve. Early on we would start the day trolling, then locate the fish with our electronics, and then deploy the baits. It’s still a technique we use to this day with great effectiveness.
When we first started live baiting, we would catch the baits, then bridle them up, hold them upside down with a wet towel over their eyes and a washdown hose in their mouths, and then run the boat like crazy off the ledge. As soon as they started any erratic behavior, we would shut down and swim them until they settled down, then run again. It was good technique back then!
All the competitive teams learned quite quickly what was going on, and bait tube manufacturers started springing up. These days, tube design and installation are continually evolving, with teams and crews constantly refining their technique. Manufacturers are also building some great new systems being developed with inline, closed loops with oxygen generators. Technology has no doubt come a long way in terms of tuna tubes, and while I’m reluctant to say I’m an expert on the latest and greatest, I have learned a few important techniques over the years that are applicable regardless of the technology you have on board.
Early on we noticed that if any part of the bait, including the tail, stuck out of the tube, the liveliness of the bait was greatly diminished, so we modified our transom tanks to make them deeper. Everyone wanted as many tubes as possible, so we went from the angled tubes to straight vertical, although I still believe the baits hold up better at an angle. As the number of tubes onboard increased, so did the volume of water necessary to flood the tubes properly.
Over the first several years we figured with medium-size skipjack, say five pounds or so, the flow rate could be as slow as 22 seconds. That timing was measured with a stopwatch by timing how long it would take for an empty tube to fill from bottom to top. In hot water, a faster flow rate was necessary. Bigger baits, such as a 12-pound tuna, did best at around 15 seconds. We always etched marks in the valve bodies so we knew where to set the necessary flow rate. Each area I’ve fished requires slightly different conditions for keeping baits at their best, but this gives you a good reference point on where to start.
We started out with 1 hp, then 2 hp, and now we run 3 hp pumps. We still prefer the Pentair Aqua Culture Pumps. Since they discontinued the Salt Water Series pumps, these have been working quite well for us. The programmable variable speed pumps have many benefits as well. We try very hard to keep the plumbing the same size as the outlet size is on the discharge side of the pump, keeping the same size all the way through the valve manifold and trunk line that feeds the tubes until the outlet side of the valve. This carries the water volume as far through the system as possible without increasing the pressure. We also install a bushing on the outlet side of the valve that reduces to whatever the inlet is on the bottom of the tube. I prefer threaded and unioned valves so they can be broken down if needed.
Perhaps one of the biggest lessons we’ve learned with tuna tubes is that any air bubbles are a real threat to the liveliness of the baits—a straight-up death sentence for them. After realizing this, we had an MIT engineer develop a reverse wedge for some boats that we put between the through hull and the bottom of the hull. It helped dramatically in most instances.
If the baits aren’t living well in the tubes, the water flow, air bubbles, and water temperature aren’t always to blame. Sometimes it’s just the bait. Many baits clamp their mouths shut tightly when dropped in the tubes. We call it lockjaw. If your baits’ tails aren’t pumping nice and rhythmically in the tube, slide your hand down along their bodies and feel the gill plates. If the gill plates aren’t flaring, it’s necessary to pry the baits’ mouths open while they’re in the tube. My mates’ fingers used to look like a German shepherd got ahold of them at the end of some seasons!
Read Next: Live-Baiting for Giant Blue Marlin
What began as a simple idea to keep baits alive longer has grown into a sophisticated system of pumps, valves and tubes that are crucial to success in certain fisheries around the world. While the technology with tuna tube systems continues to advance, the fundamental principles that guide effective bait care—water flow, temperature control and minimizing air bubbles—remain as vital as ever.
