5. Never Island.

"Just how long will this take?" Summer asks impatiently. "I must be back before evening – I have a date."

"It is my belief," the Doctor says, "that if ALL of you do exactly as the Captain says, we will all survive, and we will ALL come out of this alive. But if even just ONE person doesn't, then we ALL die. You can see that it's dangerous out there. Alan's body shows us that. We are below the surface of the water. If we open the hatch even for a second, water will cascade in and all the air in here will escape through the same hatch, leaving us all to drown. You can see that."

Vera bursts out sobbing again.

"So, here's the plan," the Doctor continues. "The boat has lost buoyancy for some reason. It is likely due to a nearby underwater landslip. What happens during an underwater landslip? Lots of trapped gasses, methane and gas hydrates, bubble up to the surface. What do we know about water with bubbles in it? It is much less dense! A boat floating on that water will lose buoyancy and sink, just as we have done. The landslip will come to an end, the bubbles will cease, and we will float to the surface again. Easy!"

"So, how long will this take?" Summer asks again. She is keen to be back in time for her date. This appears to be far more important to her than whether they all live or die. She is so preoccupied with herself that she is oblivious to the plight of herself and others.
"That depends on the landslip," the Doctor says. "And we don't know anything about the landslip."
"How long do underwater landslips take?" Tristan asks. "Landslides on land are quick and they stop soon."
"Ah, yes," the Doctor replies, "underwater landslides do take longer. Buoyancy of the slipping material…"
"Don't bore us with the details," Wayne says rather shortly. He can see the other passengers want the answer rather than the physics. "It takes longer. How much longer?"
"Hours, possibly days," the Doctor says.

"Will I be back in time for my date this evening," Summer asks. She is almost crying at the prospect of missing her date.
"Uncertain, but much more likely than if anyone had jumped ship!" the Doctor says.

"What about poor Adam?" Wayne asks. "He's dead. Won't we all have to fill in countless forms at a police station?"
"That's true," the Doctor says.

"What about the island Adam tried to land on?" Wayne asks. "I guess we didn't make it to the island?"
"There never was an island," the Doctor says.
"But I saw it with my own eyes," the Captain says. The Doctor won't get away with this one!
"You recall I said that water with lots of bubbles in it is less dense?" the Doctor says. "Then that less dense water rises and reaches the surface. It rises up above the normal height of the sea level because it is less dense and looks just like an island. Not very wide and not very high. Just the width of the landslip. Now, is that what you might have seen?" he asks gently.

"The boat moved just then," Ommera says. "Do we need to rock the boat to get it off the bottom?"
"Let's do that," the Captain says. "In time with me … to the left … to the right." He doesn't want to spend more time on the bottom of the sea than he really has to.

As they look out of the window, the wreck seems lower down than it did. Soon they can see the water running off the deck. The leak stops running. The sun is shining again.

"Nobody goes out yet," the Doctor says.
"I say what happens," the Captain says. "Why can't we go out yet?"
"Because the gasses haven't blown away yet," the Doctor says. "The air outside the hatch is still likely to be high in methane and other gasses that have bubbled up. Anyone going out now is still likely to die, whether of asphyxiation due to lack of oxygen, or poisoning due to ingestion of these gasses. That's partly what happened to Adam. Better wait a while."

"I want to know if the motor will start," Tristan says.
"And that depends on the shape of the air intake for it," the Doctor says. "If the air intake has a U bend preventing water intake, it'll be alright. No water will have entered the motor air intake."
"These boats weren't built with sinking in mind," the Captain says. "No doubt we will need to be rescued. I'll send a flare up."
"I'd wait a while," the Doctor says. "Methane is highly combustible, and there may be a lot of it about."
They all laugh nervously at the prospect of being at the centre of a large conflagration.

"Doctor," Ommera says, "I'm sorry, I really didn't enjoy this date. After my brother drowned I have a tangible aversion to water."
"I'm sorry," the Doctor says. He cuddles her closer. "I think most people here haven't enjoyed the cruise much, but at least we all survived, well, most of us."

"I wonder what the history books will say about this boat journey?" the Doctor asks. He wants to distract them from the boredom of waiting while the gasses blow away before they can go out safely.
"I hope they just say we all survived," Ommera says.
"What else might they have said?" Tristan asks.
The Doctor shakes his head. These folks have no idea. There were any number of moments where their own actions would have killed all of them. How could he tell them?
"History books might have said that the boat was found without passengers just drifting at sea," the Doctor says. "No sign of any bodies. But then there's a lot that History just doesn't record correctly. And how would we ever know differently?" He tries to divert from the main headline by diffusing a totally different argument into the mix.

"Did we just change History?" Ommera asks inquisitively. Everyone looks at her. She continues by way of explanation of the question. "We nearly didn't join the cruise. But I think we changed things."
"No you didn't," the Captain says. "Everyone did just as I said, and we all survived."

Ommera looks at the Doctor, and the Doctor looks at Ommera. They burst out laughing.

THE END

The previous episode in this series is called "The White Dress".

The next episode in this series is called "The Plight of Slint."

I hope to add further episodes soon.

Afterword.

The Story.
Many facts have been thought about and considered.
This is likely to be what passengers and crew might be faced with in such circumstances. Although most boats would let in too much water and stay down, if they don't let water in, they may stay on the surface, just about.

Underwater Landslips.
Underwater landslips do release significant amounts of gasses which rise to the surface and look like a small island for a time while the bubbles burst at the surface. Loss of buoyancy in water containing bubbles will cause a boat to go down. But if a ship is unable to close the hatches, the water will pour in and the air will go out, so the ship will go down. If enough air can be trapped inside the ship it will re-float when the bubbles have ceased production, the water has resumed its usual density and so buoyancy has been restored.

Underwater landslips occur all over the world, not just in the Caribbean! Many ships are lost unexpectedly each year, even when there are no adverse weather conditions.

People's reactions.
The choices made by ill-informed passengers or even the Captain may have dire consequences for all aboard. The desire to abandon the ship is the likely cause of many of the cases of empty boats found, yet in at least some cases it might be unnecessary.

Leaving the cabin before the gasses have blown away will lead to finding a boat full of bodies with no indication of how they died. They will never be able to light a flare to send it up!

It may be a claustrophobic and challenging experience for all the passengers!

How would you react?

The previous episode in this series is called "The White Dress".

The next episode in this series is called "The Plight of Slint."

I hope to add further episodes soon.