Worldbuilding Prompt #796 - A Tidal Wave To End A World

This post was inspired by a writing prompt in the Worldbuilding Community - Worldbuilding Prompt #796 - Tidal Wave

Image created by AI in NightCafe Studio

Comms-Lieutenant Kaver stifled a yawn. He'd been on duty for four hours, and nothing had happened. It rarely did. The fleet was inactive for the time being, sitting in reserve near the R&R planet of Blackjack-5, the ships' crews being rotated down in sequence for some much deserved leave.

Then the incoming message screen lit up. The frame suddenly flashed orange, indicating a priority distress message. Kaver hit the button, and a pre-recorded repeat message started coming through.

"This is the Aquatica IV Colony calling. Repeat; Aquatica IV. We are declaring a situation red emergency. A large asteroid has been detected on a collision course, it came from behind our sun too close and too large to attempt deflection. Please help !"

Kaver shot into full wakefulness, hitting the button that would send an emergency page to Captain Razlin. Then he clicked the respond button on the comms deck.

"Aquatica IV, this is Imperial Fleet 7233A-7 responding. We are currently in orbit around Blackjack-6. Please give us more information on your situation."

The repeating message stopped in mid-phrase, and a man's voice came over the communicator.

"Thank the gods ! Please help us, it's going to hit in less than 50 hours. It's over 40 kilometres in diameter, and is going to make a tidal wave two thousand metres or more high."

The man's voice was shaking, panicky. Kaver asked, "Are you able to evacuate to high ground deep inland ? Mountan tops ? What can we do to help ?"

The voice came back a few seconds later. "We're a water world, there is no land. None. Nothing to break the tsunami, it'll go around the world over and over for days. Our floating cities aren't designed for this, they'll be smashed to pieces. We need total evacuation, all two million of us."

At that point, Captain Razlin strolled onto the ship's bridge, still carrying a half-empty bottle of beer.

"S'up Kaver ? This better be good, we were just getting into the party spirit."

"Yes Sir !" Kaver said, "We've got a code red from Aquatica IV. Massive asteroid impact in 50 hours, a complete planet-killer, tidal waves on a water world that'll wipe them out. They're asking for total evacuation of two million people."

Razlin appeared to sober up instantly.

"Tell them we're on the way, Kaver. Then message the fleet. I want every ship moving within the hour. Tell the people planetside on Blackjack-5 their leave just got indefinitely extended. Oh, and not to gamble all their money away before we get back."