A stickbait is a type of lure that is designed to mimic a baitfish usually a decently big one and it attracts nearby predatory fish. Stickbaits are used to attract fish like Kingfish because kingfish are aggresive predators that would demolish a stickbait thinking its a juicy meal.
Floating stickbaits are most effective when the fish are feeding near the surface. If you see kawhai or mullet jumping up from the water then its a sign for uing a floating stickbait. You want to dart the lure side to side and wait for a fish to strike. This motion mimics a injuried baitfish from the school which the predatory fish see as easy pickings which lead to a hook-up.
Sinking stickbaits are effective when the fish are a little deeper or if the conditions are more choppy where a floating one wouldnt work as well. You want to lift and wind the rod while retrieving the lure which makes it dart around and mimics a baitfish. This lure catched Kingfish, snapper and other predatory fish that might be lurking.