Dark Blue Moon

At the Joestar estate, Speedwagon Foundation doctors with cutting-edge equipment still cannot ease Holy's worsening condition. Sailing from Hong Kong toward Singapore, the group learns that a young stowaway has been found in the cargo hold; the frightened child slips away and leaps overboard into shark-filled waters. As a shark closes in, Star Platinum batters it senseless and Jotaro pulls the child aboard, discovering she is a girl. Joseph then watches an unseen aquatic creature slice the shark in two, and Kakyoin uses Hierophant Green to draw Jotaro and the girl to safety from a distance.

Suspecting a Stand, the group wonders whether the girl deliberately lured Jotaro into danger, though they soon rule out any link to DIO. Captain Tennille prepares to confine her, but first pockets Jotaro's cigarette, a small act that tips Jotaro off. He accuses the captain of being an impostor and baits him into confirming he wields a Stand, admitting afterward that he had planned the trick without proof. The fraud drops his disguise and unleashes Dark Blue Moon, seizing the girl as a hostage, only for Jotaro to reverse the situation and free her with Star Platinum's speed.

Unable to haul her up because his Stand's arm is crusted with barnacles, Jotaro hands the girl to Hierophant Green and drops into the sea. The impostor explains Dark Blue Moon's tricks and whips up a whirlpool laced with razor-sharp scales to shred the weighed-down Jotaro, whose Stand is nearly covered in barnacles. Playing dead, Jotaro channels his strength into Star Platinum's fingers, extends them across the water, and cuts through the enemy Stand's head to defeat the impostor. As Joseph reaches to throw a raft, hidden bombs detonate across the vessel, forcing everyone into lifeboats, and while adrift the girl spots an enormous freighter ahead.

The runaway girl, later named Anne, is rescued from the ocean and briefly suspected of leading Jotaro into danger. Jotaro exposes the ship's captain as an impostor and Stand user by baiting a confession, revealing Dark Blue Moon. Trapped underwater with a barnacle-covered Star Platinum, Jotaro feigns weakness and defeats the enemy by extending his Stand's fingers to cut its head. The impostor's planted bombs destroy the ship, sending the group into lifeboats where a massive freighter appears on the horizon.

The sixth episode of Stardust Crusaders adapts the second half of chapter 127 through part of chapter 130. The anime adds a brief scene of Speedwagon Foundation doctors watching over Holy, and moves an early conversation between DIO and Enya to the following episode. Series creator Hirohiko Araki personally named the stowaway girl Anne. In the licensed English release the fake captain becomes Captain Dragon, a nod to the real Daryl Dragon of the Captain and Tennille duo, and the shark killed in the episode is identified as a shortfin mako.