Killer Shark, captured a couple of issues ago, is still in prison at the start of the Dillin and Cuidera cover story from Blackhawk 130 (Nov. 58).
Killer Shark's gang are still on the lose, and have a mechanical "man-o-war" machine that they are using for their piracy. It highly resembles the iron octopus that appeared in the Question Mark story just after DC started publishing this book. Blackhawk decides to impersonate Killer Shark and fake a jail break, so that he can hook up with the gang and lead them all into a trap.
The plan does not come off as smoothly as it might. The gang turns against their former leader, and Blackhawk, as Killer Shark, has to bribe one of the gang to free him. He then takes control of the man-o-war and gets the rest of the Blackhawks into the base before revealing his true identity, and they round up the gang.
Killer Shark returns the following year.