If you are trolling for tuna some ideal lures to try are tuna feathers, cedar plugs and skirted plastic lures, Rapala plugs can be used as well. One of the better trolling plugs is the Halco Max it can be used at high speeds, blue and white plus green colors work well, some fishermen have reported they remove the treble hooks with a single or double hook causing less bending, cedar plugs work well. If you come upon a school of fishing cast your line in between them, poppers are also helpful, ranger like lures skimmed over the waters surface steadily work well. One of the best poppers around are the Yo-Zuri Sashimi Bull they come in a variety of colors, tunas have great eyesight so sometimes the best thing is to keep the lure as still as possible without moving it. The shimano Ocra a stick type bait has been used to catch the tunas by riding on the waters surface quickly and as always the jigs in metallic colors are still popular when fishing in the oceans deep waters.