You’d think a cruise along the banks of the Ohio might be a low-key way to unwind on a cool autumn evening. But even though Halloween is still weeks away, the crazies aboard the USS Nightmare are already in full swing, doing what they do best — scaring the bejeezus out of whoever boards their vessel. What’s really cool about the Death Dredge is that taking the 25-minute tour is unnerving and terrifying, but not overly gory. The emphasis here is on Hitchcockian suspense over butchered cadavers. There’s some of that, but the Hollywood-quality effects and makeup, combined with uniquely weird sensations of touring a derelict ship, make for one hell of a ride. Among the new thrills for this season are reanimation tanks that were built to resurrect the crew. 7-11 p.m. Sunday, Wednesday and Thursday; 7 p.m.-1 a.m. Friday and Saturday. $16; RIP (fast pass) $20. Newport on the Levee, 101 Riverboat Row, Newport. ussnightmare.com.