This is the English version of my German Fanfic 'Überlebenskampf', translated my myself. English isn't my first language, and this isn't beta-read.

Prologue

The cruise ship was making good progress, the weather was nice and the guests were relaxing on the chairs on deck. They were returning to their home harbour, the journey was almost over now.
Harry was on deck too, observing the calm ocean, a few birds trying to steal food and his cousin stuffing himself with ice cream.
Harry wasn't quite sure why the Dursleys had even bothered taking him with them on this trip, but they probably didn't want to impose on Mrs. Figg. 'I'm not a spring chicken anymore', was what the woman would say if asked about her age, but Harry thought to himself that she must be getting quite old. Her hair was almost white now and she had trouble walking.
Leaving Harry alone in Privet Drive was also not an option, since Vernon and Petunia always said they wanted their house to still be standing whenever he suggested staying there. He didn't know why they believed he was a pyromaniac...
In the end, they decided to let Harry come with them on this trip. The tickets were a coupon for four people anyway, so they didn't have to spend any extra money on him.

It was getting dark, but Harry stayed outside while most other passengers went back below deck, either to return to their cabins or to eat something in the big cafeteria.
Harry was staring into the distance. He thought he'd seen a silhouette of an island there earlier. That was supposed to be impossible, since he had seen a map of the area when he had visited the navigator.
But the island was there, surrounded by fog that looked almost like a dark, sinister aura. Harry's gut told him that this wasn't good and his gut was always right. The ship was approaching the island. It was getting darker and he could barely make out the shape.
He went back to his cabin, but sleeping simply wasn't coming to him. Every time he tried, his uneasy feeling came back full force.
Some time during the night a storm descended upon the ship as well, shaking Harry awake from his dozing.
Harry ran outside. His suspicions were correct – the dark silhouette of the island was towering over him.
The ship was swaying harder now and a big wave washed over the deck. Harry barely had enough time to cling to the railing and avoid going over board.
But a few seconds later, that was exactly what happened. Another, even bigger wave crashed over him and Harry was plummeting down towards the ocean.
He was not the only one, more and more people emerged from the waves all around him, fighting to stay afloat.
Harry had always been a decent swimmer in school, but the restricting clothing and rough sea made the hundred or so metres between him and the beach look like an impossible journey. He did, in the end, manage to drag himself onto the beach. Everywhere around him were old ship wrecks, some of them looking like they were hundreds of years old!
It seemed that crashes like this were a regular occurrence around here... But that also meant that there was a good chance that there were other survivors on this island. It was weird that no one had ever tried to rescue them.
But Harry had bigger worries. He was soaked to the bone and even if it was July he was freezing and the icy wind certainly didn't help to keep him warm.
Harry was one of the first people arriving at the beach and he searched for a shelter near the shore. He certainly didn't want to miss the arrival of the others, because he definitely didn't want to be left alone while the others searched for civilisation!
Harry got lucky and found a small cave. The opening was overgrown with vines and tall grass and would shield him from the weather. The hole was barely big enough for Harry to curl up in, but he managed.

Harry didn't know it at the time, but this cave and his instinct had just saved his life...