A beige colt was having the time of his life as he swam among the reef. He was there with a group of ponies to learn how to dive, and this was his final exam! Swimming in the actual ocean; Just south of Seaquestria too! He couldn't believe his eyes. Lion fish, Clown fish, Triggerfish, Hawkfish, all were swimming around him among the sea sponges, anemones, and corals. Going back to the surface, he looked around, and still saw his group, and the boat that they came in on, so he figured he was fine.

Diving back down, a seapony swam up to him, one of the safety rangers.

"You might want to swim back to your group kid. It's very easy to get lost, despite how shallow this water is. Follow me." She said calmly, before turning to lead the young colt back to his diving group. He followed obediently, having heard the stories of ponies who had gone diving, then either got lost or left behind... most never made it back. As he rejoined his dive group, his instructor did a simple roll call on the surface.

"Okay everypony, stay together as a group. We'll pair up in a little while. Don't touch the lion fish and urchins, they're poisonous;" the deep blue mare warned. "While they won't kill you, it will be very painful. Mind your distance with the sharks. If you can see them, they most likely will leave you alone. All that aside, stay calm, and don't panic. Last thing anypony wants is the bends, which we discussed in the classroom. Who remembers what the bends are?" she asked.

The young beige colt raised his hoof first. "Miss Sea Star?" He asked.

"Yes, Tide?"

"The bends ma'am, is also called Decompression sickness. When the diver rises too fast and gets bubbles in the blood." Tide Pool answered, putting his hoof back in the water. "And the symptoms can be anything from a small rash, and joint pain, to death. And the only treatment is a Re-compression chamber."

"Well done Tide. Glad to see young ponies so interested in the seas." Sea Star smiled. "Now, how much to we want to float on a full lung of air?" She asked. Another pony raised her hoof.

"We want to keep just our eyes above the surface ma'am?" She answered nervously.

"Good. Now, lets do just that." Sea Star smiled as she took in a deep lungful of air. The class followed her example without hesitation. Tide Pool calmly got to finally use the skills he learned in the classroom and pool, in the real ocean. Behind his calm facade, he was ecstatic. Ever since he got his cutie mark, He's wanted to explore the sea more, and was unable to resist it's call. To swim with the dolphins, photograph fish as they swam, maybe see a whale, and if he's lucky, maybe discover a new species! They did only recently rediscover an ancient fish long thought extinct... So why couldn't he?

The seaponies hired to keep a watchful eye on any stragglers and wanderers also made a very clear warning earlier that day. To stay away from the Blue Hole. Why was that? Why stay away from a blue hole? It was just an underwater sinkhole after all. As he swam with the class, he began to hear a near unmistakable sound. A low, deep rumbling wail from the distance.

"OOOH! Your in luck Class!" a seapony called excitedly. "We got Humpback Whales swimming by on their migrations! Follow us and you'll get to see them"

Whales!? Real whales!? Here? Now? And humpbacks too!? Oh was Tide Pool ever so glad he brought his underwater camera! He was sooo going to enjoy this! Quickly swimming to the front of the group, Tide Pool raised his camera and followed the seaponies to the edge of the reef.

There, off in the distance, was two pairs of Humpbacks. Two cows, two calves. Their calls and songs entranced young Tide Pool. Raising his camera, Tide Pool focused on the whales. Their songs, sounding both mournful, but full of life. Their grunts and groans... It was a language all it's own. Their long pectoral fins and tiny dorsal fin. It was majestic to watch. He must have snapped at least a dozen photos before remembering he had only so much film.

"Beautiful, aren't they?" asked a seapony next to him. He nodded in affirmation. " They're swimming to the polar north for their feeding grounds." She explained. "They like the warmer waters for having babies. Gives the calves time to build insulating fat reserves to keep them warm in the colder waters during migration." Tide already knew this of course, but was too enraptured by the majestic animals in the distance. All the divers then swam to the surface as one of the cows began to dive.

Tide followed closely, readying his camera for one more shot. Breaking he surface, he aimed carefully, and waited; His hoof hovered over the shutter lever, like a rattlesnake waiting to strike an unwary mouse. Then, like clockwork, one of the Humpback cows broke the surface. The whole body nearly flying completely out of the water as Tide Pool struck the shutter, before coming back down and making a tremendous splash. The crowd of divers cheered, whooped and hollered at the display, unable to believe their luck! First time in the ocean and they get a free whale watching excursion? How often does that happen?

Diving back down, Tide began to explore the reef as the whales made their departure. This was already the best day ever(!), so, time to explore. The sounds of the sea were just as astounding as the sights. If he listened, he could hear all kinds of sounds. Dolphins, Whales, it was amazing. The sounds of birds splashing and catching fish. As he listened, he photographed. Clown fish in their anemones, crabs crawling along the sea bed, whole schools of Angelfish, even the corals themselves.

It was then he saw the biggest fish he'd ever seen. A Giant Goliath Grouper, as big as he was, or maybe a bit bigger. As he raised his camera, the fish jolted and began to swim away. The young colt, determined to come home with at least one photo of such a large fish, gave chase. He paid little attention to where he swam or to how far away from his group he was; He was going to have proof of this large fish, lest his friends and older sister claim his stories to just be "Fisherpony tales". Before he knew it, the grouper dove straight down, into the dark blue below.

Tide, suddenly knowing how far away from the group he was, stopped his pursuit, but aimed his camera anyway. As he aimed, the fish got further and further away. Suddenly, a new sound met his ears. It sounded like a young whale's cry, but much higher in pitch. Oh if only there was a hydrophone with him. As his hoof met the shutter lever, a bright green flash erupted from the deep blue, striking the giant grouper. The fish, once alive and moving vibrantly, shuddered, then stopped moving. Much to Tide Pool's surprise, it began to rise. Then came that call again. That call... what was that? He'd never heard a call like that before... It was almost... musical, and not like the Humpbacks from earlier. This was as if something down there was... singing. Literally singing, as if humming a lullaby.

It was then Tide Pool realized that the Giant Grouper he was chasing was now dead, and limp. It's swim bladder carrying it back up to the surface. Maybe he could ask the Seaponies if he could take it home for dinner? He did have a pegasus for a father and sister after all. His hoof never left the shutter lever of his camera. Looking down at the counter... shoot! 3 frames left... Still looking down into the deep blue below, he noticed something off... another light... no... wait... there's two lights. As if a pair of eyes was watching him. His hoof gently pressed the shutter lever again.

Suddenly something swam up and grabbed the Grouper. His hoof slammed down on the lever as quickly as he could. As best as Tide Pool could tell, it was that blue-ish green of shallow sea water. It bit down on the grouper, also grabbing it with what appeared to be clawed fins, similar to seals. As it did, the high pitched cry returned. Immediately after grabbing the dead fish, It began to dive. Slamming his little hoof on the shutter lever again, he saw the creature's tail. It was a fluke... similar to a whale or dolphin's fluke, before it disappeared into the deep blue below. As it swam away, he heard that song again; That gentle lullaby. Tide Pool couldn't help but keep his gaze fixated on those dark waters.

That is... until a fin grabbed his shoulder and spun him around. There, in his face, was a mildly irritated seapony stallion.

"I thought we told you to stay away from the blue hole! Your not here to dive deep." He said, annoyed. "C'mon Tide. Back to the group. And you were doing so well." The stallion grumbled lightly as he escorted the colt back to the group. The group was nestled into a small sandy hole in the middle of the reef, doing a head count. Sea Star immediately looked relieved upon seeing the young colt, then annoyed when the seapony safety guard told her where he was found. Tide, unable to speak only looked sheepish as he was berated with his instructor's eyes. She then motioned for the class to rise to the surface.

The class, following their instructor, rose up slowly to the surface. Tide Pool couldn't help but feel guilty, having disobeyed the Seaponies... Was that thing why they said to stay away from the Blue Hole? He had to find out more... Climbing back aboard the boat, he undid the diving rig strapped to his barrel, unable to get that... song... out of his head, and that glow from his eyes... Was there something down there the seaponies DIDN'T know about?

"Congratulations everypony, you're now certified divers. You'll get your temporary licenses signed when we get back to shore. Even you Tide." Sea Star said joyfully, before adding "Please don't disappear like that again... You know never to wander off or dive alone. Just about gave me a heart attack."

Before they began to propel the boat back to shore, Tide wandered over to one of the seaponies, now a hippogriff.

"Sorry for wandering off... I was just... trying to get a picture of a Goliath Grouper... darn thing was bigger than me!" He explained. "But... it dove into the hole."

"Next time, let one of us know okay? We're not mad kid, just... ugh... don't do it again." He said calmly with a gentle smile.

"I gotta ask though..." Tide started. "Is something living in that blue hole?" The hippogriff looked confused.

"What do ya mean kid?" The green hippogriff asked.

"I mean, when that grouper swam down, I saw... a flash of green light, and suddenly the grouper was dead. I saw glowing eyes, Then something then swam up, grabbed the fish, and swam back down... I don't know if I got a picture of it... but I hope I do." Tide said, fidgeting with his now empty camera. The hippogriff looked thoughtful, pondering what the colt had just told him.

"I wouldn't worry too much about it, Tide. There's all kinds of creatures out there. Could've just been an eel or something. Morays can get pretty darn big." He explained with a smile. "Why don't ya just park it, and enjoy the ride home?"

Tide, having no better explanation or anything to do, did just that. He watched as the dolphins began to play in the wake of the boat. their jumping, and splashing, some even spinning. But Tide couldn't get that sound out of his mind still. Even when Sea Star shook the young colt from his stupor, he still heard that sound. He filed off the ship, with his class, staring at his camera...

"What are you?" he asked himself quietly.

"Here ya go Tide! One temporary diver's certification. You'll get the real deal in the post next week." Sea Swirl said excitedly. Tide's attention was suddenly, and fully on his new certification. His mood had gone from somber curiosity to excited faster than a changelings shapeshift. Best day EVER!

~~~~***~~~~

As Tide came out of the photographer's shop with his father, envelope in his saddle bags, He regaled the details of his trip to his pop.

"Have fun out there champ? See plenty of fish?" His father, Redwood asked.

"Oh heck yeah! Even saw a few Humpback Whales!" Tide Pool chattered excitedly, practical bouncing on his hooves.

"Humpbacks?! On your first ocean dive!? That's awesome! Please tell me you got photos of that!" Redwood said. "I've only seen them from the sky."

"Oh yeah, about a dozen of them. It was so cool!" The beige colt exclaimed loudly. "One of them even breached!"

"Aw darn... now I really wish I had gone with ya! I'd have loved to have seen that." The rust colored pegasus smiled. "At least ya took pictures. Maybe we can frame some. Now let's get a move on. Your ma and sis are waiting."

~~~~***~~~~

The young colt excitedly ate a congratulatory dinner made by his mother. Even his normally teasing sister was happy for his success. That night, he carefully looked over the final three photos. The first... Of the eyes, he didn't know if they were watching him, or the dead fish. The second... Of the creature itself grabbing the fish. The third... of it's tail fluke, as it disappeared back into the depths. It was strange... He'd never seen such a creature, not in any of his books on sea life.

"What are you..?" Tide Pool asked to himself.

Author's Note

Something new... Speaking as a diver, I've always been fascinated by the sea; And I've always been interested in the idea of something large, and unknown, hiding beyond our reach, and as such, Various medias that explore such an idea I find fascinating. Such as Subnautica, Waterworld(Even though the sea monster is a 'blink and you miss it' moment), Meg, and similar.

The media that mostly inspired this, is a canceled TV series called "Surface". I recently got my hands on the box set of the one and only season, and have begun to re-watch the show. Now the creatures in the show are (SPOILER ALERT!) genetically engineered, but instead, I've tweaked the origin, and habits of the creatures. The sound effects, rather than what the show used, I'll let my nerd out a bit more and say they were inspired by the Legendary Pokemon, Lugia. If you remember those sounds, or just looked them up, good on you.

Constructive criticism is always welcome. Shoot, If you ask, I might include your OC in a select role in a few chapters. More details to come.