Two countries are trying to end a war between them, despite factions on both sides that want the war to continue. To protect the peace talks, they are held out in the ocean in a secret location protected by Aquaman. Unfortunately, the bad guys have an uncanny ability to find the ship, despite all of Aquaman's precautions. Then Aquaman notices that a swordfish hasn't left the area, and is practically clinging to the ship, despite his orders to evacuate the area when the bad guys launched a torpedo. He kills the swordfish, which is actually a robot, and the peace treaty is signed and safely delivered.
An interesting mystery with some urgency. You don't know how the bad guys are finding the ship, but you know Aquaman has to stop them from destroying it and all chances for peace. As in any good mystery, the swordfish is shown early on, but the significance doesn't become clear until later.
Aquaman uses a lot of fish in this story. Octopi protect the ship with steel pieces of hull, flying fish net a gunner, whales work with squids to blind a plane... You get to see the range of Aquaman's finny friends.
A very cool scene is the panel where the whales blind the plane. You get a sense of the movement of the plane along with the power of the whales. In the next panel, with the plane crashing, the arc of water that shoots up is drawn perfectly.
The countries declare the date of the peace treaty to be Aquaman Day.
A pretty good story. Worth searching out.