There were gaps all along the line, and regular Iron Island ships moved up into them. These ships had no guns, but they had special catapults designed to launch kegs containing anti-magic statues. The kegs would float and nullify the magic spells Zonian mages used to make their ships invisible. As the kegs were launched, ships began to appear and were instantly bombarded by the ships along the line. Zonian mage ships went down one by one without ever getting into range to use their spells against the Westeros fleet.
The Zonian naval general Jun Wei sat at his desk, back in the middle of the invasion fleet. He shook his head disgustedly at the reports of losing many of his hidden mage ships to tricks. He ordered the remaining mage ships to turn and rejoin the body of the invasion fleet. 20 of his ships had been sunk with not one casualty on the Westeros side. "This would not stand!" He ordered both the sling ships and attack ships to the front to engage this enemy. He would show the true might of the invasion fleet to these lesser beings.
Captain Dirk watched with deep interest as the enemy mage ships fell back out of range. The intel teams expected this, and the Zonian fleet's next move would be to bring its sling ships to bear on the Westeros ships. Then they would advance their boarding ships to grapple the ships near them. "Prepare to weave, lads! And be sharp about it. Watch the sling distances closely and move accordingly!" Dirk shouted out. The Brandon's Rest fleet began to weave, bringing 6 ships to bear on their front, firing at will against the encroaching ships. The other six ships that had just fired would weave in a figure eight to bring their guns to bear on the other side. The whole line would slowly retreat out of range of the sling ships' bombardment, while their guns would slowly wipe the enemy ships out. This was happening all along the front of the naval battle. From west of King's Landing all the way north, where the Brandon's Rest fleet was.
Gunships from the Iron Islands and Braavos held the center of the line, with King's Landing ships in the south; all were doing the same maneuver. When the enemy finally committed all its ships to move forward, the fleets would retreat past the wildfire zone. This was the attrition plan devised by naval advisors against a much larger enemy. The distance their guns could fire was the fulcrum on which the Westeros fleet sought to break the enemy invasion forces. And it was working all along the line. The Zonian sling ships would tentatively fire to gauge range, which would fall a 100 yards short, and then move forward under fire from Westeros guns. Dozens of Zonian sling ships were destroyed, and another 30 attack ships had also been sent beneath the waves by the concentrated gunfire.
Back in Brandon's Rest and King's Landing, intel groups were ticking off the destroyed enemy ships as telepaths reported each kill. Tyrion gave a funny look and said, "100 down and 1400 to go." Those in the command room nodded in agreement. Belaletrix said, "So far, so good!"
In a balloon along the coast at Sea Dragon Point, Penny and Bart were once again on duty. Bart was scouring the ocean's horizon in search of telltale signs that invisible enemy ships were approaching. Suddenly, he spotted three clear wakes on the surface of the sea, less than a mile out from Brandon's Rest and quickly approaching the Bay of Ice. He relayed the coordinates to Penny, who sent them on to the gunners at the coastal forts, the fortress on Bear Island, and the walls of Brandon's Rest. The larger guns all opened up on the coordinates, and two of the enemy ships were damaged enough that the invisibility spell failed. They were quickly sunk. Bart told Penny two were down, but one was still invisible and incoming. She relayed this message. The guns adjusted for closer range and opened up again. Again, an enemy mage was wounded enough to drop the spell, and that ship became visible and was sunk as well. Bart called out, "All clear!" and when the message was sent, the guns fell silent again.
While it was clear that the plan had worked to perfection so far, all along the line, enemy ships were doing their best to overwhelm the Westeros fleets. A few casualties were taken, and small damage was done by sling ships firing, and in one case, an attack ship had gotten to within grapling range before it was blasted out of the water. The call went out to retreat past the wildfire zone. And the Westeros fleets turned and ran into the wind.
The Zonian ships charged after them, thinking they had them on the run at last. Jun Wei signaled his fleet to send the full first wave after them. Fully 500 ships charged after the retreating Westeros fleets, but the retreating fleets were faster as their wind users were well rested. The Zonian ships' wind users were mostly captives, exhausted from the long voyage across the becalmed zone. The Westeros fleets all made it to the next staging area and set up for the weave again.