I have taken up the challenge of catching big blue catfish on ultralight lines and would like to pass on some of the hard-earned knowledge to those looking to try it for themselves. This really only applies in relatively open water with few hang-ups. Let's use 4 pound test for this discussion. Heavier lines will still be valid within this application, there will just be more room for error. I personally use Ande Tournament monofilament. This is a very high grade line that will break at or slightly below it's rated strength. Many brands will overtest and cause you to lose that record if ever you are lucky enough to catch it. It carries a hefty price tag, but in the overall picture it's well worth it. For the reel, I prefer a casting outfit. The line pulls straight off of the reel and doesn't make that sharp turn like it does on a spinning rod bail. Another real plus is that the line won't twist on a casting reel. It is inherent in the design of a spinning reel that the line will twist, and with the number of times you will gain and lose line while fighting a big fish there can be a significant amount of twist, and this will weaken your line over time. Remember, monofilament will lose about 10% of its strength after soaking in water for a period of time. You need every advantage fishing with an ultralight. My personal choice for the reel is a Shimano Cardiff 100. It has a very smooth drag and has a very low inertia on the start-up of the drag. I actually have to look at the reel to see that the drag is pulling - I can't feel it start. This is very important when a fish surges - if the drag doesn't give smoothly and immediately the line will break. And that drag is going to get a workout! I preset the drag with a scale. I put a big curve in the rod and set the drag at about 30%-33% of the rated line strength. This is about 1-1/2 pounds for the 4 lb test. Later in the fight, when the fish weakens, I will add a slight amount more drag, maybe 1/2 pound, but it leaves very little room for error on my part while fighting the fish. For the rod, you will want a long, soft rod that bends smoothly from tip to butt. The rod has to absorb the runs and surges of that big blue cat, and a stiffer rod with a fast tip (most of the bend in the top of the rod) will not protect the line. The soft, sweeping curve of a long, soft rod will pick up those surges and give the drag more start-up time. Another advantage is that the rod will be loaded fairly deeply most of the time, so when a fish turns toward you or runs upwards you will have pressure on the fish longer and can catch up with it before the line goes slack. I use a 7' ultralight with a long handle. My favorite has 10 guides to keep the line curve smooth. It feels like there is no backbone at all to the rod, but it actually does a supurb job. As it happens, this one is a Shakespeare Ugly Stik Ultralight and the local sporting goods dealer ordered it for me since I couldn't find one in stock. For the terminal tackle, I use a swivel, then a 4' length of 20 pound test leader, then another snap swivel, then a snelled hook. The IGFA allows 6' of any test leader, and it is absolutely nessary for protection against the spines of the fish and any trash, rocks, etc. in the water. With this set-up, I prefer 2/0 circle hooks or 2/0 to #2 kahle hooks. There is very little hookset required with these and they don't need a big bite with the gap because you won't be able to put enough pressure on the fish to have it pull loose in most circumstances. The knots I use are all palomar, and I use a lot of care when tying them to make sure that the loop doesn't twist. This will keep the knot as strong as it can be - remember, you only have a couple of pounds of strength to start with! This info is the best I have found so far. I have caught many good-sized cats with it, the best boated so far has been 38 pounds (about an hour), although I have had much bigger fish to the boat and managed to lose them one way or another. The largest on ultraligh that I have managed to lose at the boat I estimated at 70+/- pounds and had fought for hours into the dark and just wasn't prepared with enough light to see the fish soon enough to net it properly! I sure won't make that mistake again! Good Fishing and Good Luck!