It's a little long. I'll try and trim it down by 50-100 words. I may also rewrite the part with the vortex itself.
As Kaddo’s canoe slugged across the boundless surface of ocean – with a flat level of salty water as far as the eye could see in every direction – its young passenger finally glimpsed the sticking tip of an iceberg. It was the first sign of his approaching the South Pole. The aspiring waterbending master reached down and slid his thick, woolly Water Tribe overcoat back over his shoulders. He had shed it earlier when heated sun, combined with the exercise of his journey had caused him to sweat. Now the changing weather between the southern coastline of the Earth Kingdom and the South Pole made him reverse the step to stay warm in the frigid climate.
Kaddo was on his way back to his village, to the home of his Uncle Sokka and Aunt Suki. He had left Faxian Island two days ago, after parting ways with his father, and it would be two days more before he reached his destination. He longed for the good times and the innocent years when things were simpler, when he was sparring with his brother Tenzin and picking on his sister Vameira. While Kaddo prayed to the Moon and Ocean Spirits for the safety of his family, he was beyond reach and unable to help them. It was a rare sight to see Avatar Aang, gentle spirit and savior of the world, so vulnerable. However, before they parted ways, Kaddo’s father had all-but told him that the only thing keeping him from a mental breakdown was knowing at least one member of the family was sage. Kaddo could not refuse him, and thus was departing for home like a good boy – and saw no great adventure in his immediate future.
His only company now was his grumbling stomach. Having finished the bag of fruit he brought from Faxian Island on the first day, Kaddo now surveyed the water in front of him for a meal, ready to waterbend. But as he did so, the salamander seagulls flapped their scaly wings over his head – being to salty water what vultures were in the sandy desert.
“Leave me alone, you pests!” Kaddo shouted irately at the distracting reptile birds.
As he shouted out. The traveling waterbender was confronted by something far more distracting. The very sky ripped apart in front of him, and a dark vacuum imposed itself between him and the iceberg which lay ahead.
“What the-?” Kaddo began – but he could not finish his sentence. After trying in vain to steer his vessel to the side of the gaping portal, Kaddo felt his body swept up by a new current of unknown origin – away from all he knew.