On a tuna head boat you're going to see some of the biggest tangles you've ever dreamed of. I guess everyone has an opinion on bait setups but IMO forget about wind-on leaders and power pro, keep it as simple as possible. The tangles are the worst during a hot bight so the quicker you can get re-rigged and back in the water after a major tangle (or fish) the better your chances are to hook up.
For line everyone has an opinion and personal preference, I suggest you spool the reel with 80# momoi diamond in clear, it has a breaking strength of 122LBs with only .90 diameter so you can fit a lot of it on the reel. I also like Berkley Big Game 80#, it's not quite as strong but it's cheaper. 100# is fine but your capacity on that reel will be limited and you won't be able to crank your drag tight enough to make a difference in how much pressure you can put on a fish. Plus 90% of the time I'm fishing with 40# to 60# leader so the only real advantage is protection from the keel rub and other lines in a tangle. Lately I've been spooling my reels with 60# Momoi Diamond and haven't had any issues.
For the terminal rig, thread on a 6 to 12 oz egg sinker (depending on current) onto the main line, then tie on a 220 - 300 spro barrel swivel (not "power swivel", they suck). From there use whatever leader material and test you need to get a bight. I start with about 8' of 60# floro and go from there. The leader length has to be short enough so you can wind the sinker up to the tip of your rod and the fish will be within range of the gaff, too short hurts the bight. If the bight is on and they're not leader shy I'll go up to 80# floro or use the same 80# as my main line (I'm cheap). If the bight is slow or non existent I'll drop down to 40# floro to try to get a bight, no lighter than that or you'll cause a huge tangle because you can't control the fish. If it's rough and the fish are really line shy you may want to keep your bait further away from the sinker, to do this you can attach a bank sinker with a rubber band 10' or more up from your swivel, you're more prone to tangles with others with this setup but it might help get a bight. With that setup you just reel the sinker up to the tip, break off the sinker and reel in the rest of the way.
For the hook I like the standard Gamakatsu J style tuna hook, bring a range of sizes from 4/0 to 8/0. I like 4/0 - 6/0 for sardines, and 6/0 to 8/0 for butters and squid.
Remember to reel in and let out your bait very slow, you'll get less tangles and you'll be surprised how many bights you get while reeling in or letting it out.
Don't forget to bring a few squid jigs!, your mahi rod should be fine for that.
Hope that helps.
This post edited by Jigalow 09:38 PM 08/20/2008