The number one lure for Tarpon is the DOA Bait Buster Trolling Model in the PD color (Purple Demon). Also effective are several of the Mirrolure line (The fish are often picky about colors). These Tarpon should be post-spawn, which means you have a great shot at getting them to eat after their long journey offshore, spawning and then traveling back. They have one thing on their mind -- food.
They will start to thin out after the major moon phases of July, moving to many different areas. With the DOA Bait Buster you don't need to twitch it erratically to get the tarpon to eat it. Just a straight and steady slow-moving retrieve works best. Also watch the tarpon first before you approach to see what their mood is and the direction of movement. See if they are greyhounding (moving fast and in a straight line quickly in a rolling motion on the surface). These are very hard fish to get to eat. If they are milling around, daisy chaining, slowly moving northbound, these are easier fish to get to bite.
Keep all motors off and try to setup very far away from them and let them come to you. When making your cast don't drop it right on top of their heads. Try and lead the bait away from them and work it on a angle back towards their path and into their line of sight. If they are hungry they will eat it. I attached a photo of the DOA Bait Buster Trolling Model in Red/White color.
Good Luck and let us know how you do. Also check out this tarpon article.
Captain David M. Rieumont