Aqua-Melvin seemed fairly inept with his powers and performed various pranks while on duty. The main mission of the issue was to reclaim an undersea treasure from ruthless treasue hunters. The crew were convinced Melvin was undermining Aquaman's efforts. Actually some of his actions were prearranged with his partner. While the treasure hunters were paying so much attention to Melvin's actions, they failed to realize what Aquaman was up to. Leading to defeat and captivity for them.
The story implies Aquaman's powers derive from his blood and can be passed to others through transfusion.