Jack

Jack sneezed, sending a cloud of sand up around his paws. He only laughed, continuing forward towards his goal: the reef. He knew what was waiting for him there, and he couldn't get there fast enough.
The sand burned beneath his paws but Jack didn't care. He trotted faster, not wanting to break out in a full run. His leg still hurt from his adventures on the cliffs yesterday and he didn't want to make it worse. Jack was so focused on the reefs that he wasn't watching the ground, and didn't see the bird until he was on top of it.
"BRAACK!" Jack jumped at the sound, letting out a surprised yelp. The seagull he'd nearly stepped on continued squarking indignantly at him, and he grinned sheepishly, continuing on his way. When he reached the shoreline he closed his eyes happily, letting the cool waves lap at his paws. The contrast of the burning sand and the cool waves felt amazing, and he walked forward. Once the water reached his shoulders, he began to paddle, slowly at first and then faster when he got used to it. He could see the reef getting closer and he grinned, swimming even faster until he reached it.
There was a small reef shelf that was taller than the rest, and this is where Jack was going. Standing on it, his shoulders and up were above the surface.
Jack looked down into the water and laughed happily. Here they were! His friends! Of course, the fish didn't know they were Jack's friend, but that was beside the point.
Jack took a deep breath, and, with the practice of someone who did it often, slipped beneath the waves with barely a ripple. He opened his eyes, ignoring the slight burn of the salt water, and looked around. Bright tropical fish darted amongst the coral and sea plants. He followed a small yellow fish as it swam erratically from hiding spot to hiding spot. He loved these fish. Their bright colours, their quick movements, the way they always seemed to be on an important mission until they changed their mind and darted somewhere else; they were beautiful and made him very happy to watch.
After a bit Jack began to feel the burn in his lungs that signaled he needed to take a breath of new air. He swam back up to the surface, resting his feet and the weight of his body on the reef, and closed his eyes, leaning back to let the sun warm his face.

Yes, he was very happy.