Severus' meditation was broken by the sound of splashing. Opening his eyes, the wizard was surprised to see the same creature he had spotted a few hours ago. What was more shocking, however, was seeing the rest of the creature. It was humanoid, short, and lean with black skin that had small sections of bright blue and green intermingled within it. It didn't have any hair- though there were bright blue fins that laid upon its head in a stripe down the center- and it's ears stuck out of its head similar to an elf's, but longer. There were pairs of gills running from the eyebrow line to over his ears and down his neck, but Severus couldn't see exactly where they stopped from his viewpoint on the ground. The Potions Master then deduced that it was a male by its thin hips and lack of breasts, as there was no genitalia that he could see.
However, the thing that was being extended towards him from the crouched being's hands held most of Severus' attention due to its putrid stench. It was a dead fish whose head had been sliced off.
"Please eat this. I'm sorry I can't find something better for you. But don't worry, it tastes good once you get over the smell."
Severus wondered when he would stop being shocked by the male before him. The being seemed to be hissing at him in an attempt to communicate. It sounded peculiarly like the Parseltongue the Dark Lord always spoke to Nagini with.
He was obviously a magical creature. Perhaps he wanted him to eat the disgusting thing? Severus sighed. "I cannot eat raw fish."
Emerald eyes widened before the male brought the fish up to its thick lips and took a small bite with sharp, pointed teeth. The being swallowed and held the fish back out to a shocked Potions Master.
"I-it... good."
The being could speak English. Though his speech was broken and horse, Severus' mouth fell open just a tad."You... can understand me?"
The being nodded swiftly before giving the fish a little shake and putting it down next to Severus' limp hand. He quickly turned and dived back into the water, but before Severus could call out for him to come back, the Potions Master saw the top half of the being's head resurface with the gills still out of the water working frantically. Severus suddenly realized the reason behind the sudden departure. "You can't breathe air?"
The being closed his eyes and shook his head in the negative before reopening them to flick his wide, innocent gaze from the fish to Severus and back again, encouraging the injured man to eat.
Severus sighed again, feeling a headache beginning to form despite all the other pains that racked his body. His magic may have been healing him, but it was doing a bang-up job without any of his guidance.
A thought occurred to Severus as he looked back to the concerned creature still staring at him. "I can't eat raw fish," Severus repeated, "but I could eat this if you got something for me."
Severus saw the being's eyes widen and then narrow, and he nearly scoffed at the obvious display of emotion. He had a life debt to this being however, so Severus couldn't be too rude to him.
"It's nothing strenuous, I just..." Severus dragged off as he grit his teeth. Of course he had to be struck by lightning. The Potions Master sighed and continued, "I can't move. I have my wand strapped to my left arm. If you could get it and give it to me, I could eat the fish."
The being's eyes widened again before he ducked back under the surface. However, Severus remained calm, and moments later the male re-emerged to climb out of the water.
He hovered over Severus for a moment before kneeling down on the rock and gently shuffling the wizard's cloak around with his wet, webbed hands. As Severus watched the water droplets get absorbed into his robes, he made a mental note to make all his clothes impervious to liquid. When he had originally gotten his clothes, Severus had denied having the expensive spells applied, as he was a Potions Master. However, it seems that he had overlooked the possibility of getting wet from other liquids.
Severus flinched when the being's cold hands suddenly touched his skin, and the male hissed lightly in what seemed an apology before withdrawing, the wizard's wand clasped in his black and blue hand. It was then that Severus received yet another surprise, though this one was more unpleasant than the others.
The being hissed again as a small jet of green sparks flew from Severus' wand. The Potions Master cursed his versatile wand wood softly before he lifted his arm, grabbing the attention of the distracted magical being.
"S-sorry..."
Severus sighed lightly at the apology as he held and reconnected with his wand. He didn't have the strength or the concentration to be mad right now. He just needed to heal himself the best he could, get rid of the life debt to this creature, find that blasted Potter, give him his letter, and apparate back to Hogwarts.
"Accio Wiggenweld potion and burn paste."
The male watched curiously as the two jars floated out of Severus' emergency potions stash and unsealed themselves. The Potions Master used his magic to guid the wiggenweld potion to his mouth and hold it there as he drank the entire bottle. Severus had long since become accustomed to the terrible taste of potions, so the man easily relaxed his head back onto the rock he laid on to allow the potion to do its job. In a matter of moments, his head began to clear and the soreness in his arms and legs receded enough for him to finally sit up.
Growling lowly at the pain, Severus reached for the burn paste and noticed the magical male had retreated back into the water again. It was only bewildered emerald eyes that watched the wizard as he found the most affected areas of his body and generously distributed burn paste to them.
Feeling wholly better than he had when he woke up, Severus tucked his depleted supplies back into his emergency kit and turned his gaze to the interesting creature looking up at him from the water.
"You were the one who pulled me from the water and placed me here, yes?"
The creature closed its eyes and nodded before climbing back out of the water. He looked at Severus shrewdly for a moment, his forehead crinkling, before he copied Severus' sitting position on the ground.
The Potions Master ignored the obvious lack of knowledge the male had in order to say, "I owe you my thanks."
The being smiled widely, showing off his sharp teeth, before he closed his eyes to shake his head. Severus' lips thinned in distaste as he realized getting rid of his life debt may be harder than he originally though.
Staring at the magical creature as he thought of exactly what to do, Severus cursed when his mind finally caught up with what he had been seeing.
"Potter."
The creature- no, the Boy-Who-Lived turned curious emerald eyes- the same shade as Lily's- onto Severus as the wizard's face darkened. The Potions Master looked at the boy's form in mounting anger.
"What have you done, you stupid boy?"
Severus watched as Potter's face went from confused to scared in a matter of seconds. The transformed boy quickly scrambled up to dive back into the ocean, but Severus was faster.
The enraged wizard grabbed Potter's wet leg from where he was sitting, but the idiotic boy was already halfway into the water, inevitably pulling the injured professor in with him.
Closing his eyes and gasping on impact with the cold, salty water, Severus fought to keep hold of the thrashing boy and get to the surface for air. However, the recent trauma and change of element did Severus in, as Potter managed to slip away and the Potions Master struggled to swim with his waterlogged robes.
Severus cursed as he sank, not believing his idiocy. He had let his wand slip from his fingers when he lunged after Potter, so attempting a magical escape was impossible. And whatever he had said had obviously scared the brat, so it would be improbable that he would help Severus again. The only person who could save him now was himself. The Potions Master was already too deep though, and the need to breathe was getting stronger by the second.
After a few minutes of fruitless kicking and arm-waving, Severus resigned himself to watching as the surface got further and further away. The need to breathe was clouding over his thoughts and burning at his chest, but Severus could only think of Lily as his consciousness started fading away. I failed you, Lily. I'm sorry.

-

"You're going to let it die now? What a waste of time."
"Well-"
"And here I thought you were finally getting over your silly fear of those 'Dursleys'."
"...fine."

-

Severus gagged as his consciousness rushed forwards. The smell of something rotten filled his nose. The Potions Master couldn't even open his eyes before he turned his head and threw up.
Gasping as his stomach finally started to settle after minutes of the suffocation of retching, Severus opened his eyes and noted that he hadn't eat anything in nearly a day, so all that had come up was mostly water and bile.
Severus pursed his lips in disgust before turning back to see the brat crouching in front of him with a handful of seaweed.
Severus opened his mouth to curse at the fact that he now had two life debts to this child, but not a single syllable came out as the wizard started coughing horsely.
Grabbing for his wand blindly, Severus mentally clicked his tongue as it was put right into his hand. His own inability to do things by himself was starting to get on his nerves.
Non-verbally casting vacuo, the lung-clearing spell, Severus slowly managed to get his coughing under control. Taking deep breathes, the Potions Master reluctantly decided that the best way to deal with the scared child he owed two life debts to was with at least a little bit of patience. Though if the reason behind his appearance and presence in the ocean was anything less than satisfactory, Severus thought to himself, Merlin help the brat.

-

"Are you alright now? Do you need anything else?"
Severus sighed lightly as the silence he and the fidgeting Potter had been sitting in was finally broken. He looked down at the emerald eyes that were watched him from where the eleven-year-old was in the water before continuing to eat the fish he had cooked with some small bluebell flames. "English please, child. I cannot understand Parseltongue."
Emerald eyes blinked before Severus saw them fill with curiosity. "P-parsss- parssasss- parssssen-"
Severus swallowed his bite of fish- which was, as the child had said, 'good'- before repeating, "Parseltongue. It is the language you are speaking, the language of snakes."
Severus watched as the child's emerald eyes filled with understanding, and then shining stars, before he cried, "water ssnakessss!" with his arms lifted in the air jubilantly.
Severus expertly hid his annoyance, and asked, "Do you mean eels, Mister Potter?"
The eleven-year-old seemed very excited, as he smiled widely at Severus, held up his hand in a 'halt' motion, and dove under the water.
The wizard sighed, shook his head, and ate the rest of his fish. It seemed patience was working, but the language barrier was going to become a nuisance very quickly. There would be a lot of guessing and yes or no questions in the upcoming conversation- of that, Severus was certain.