I couldn't get any ideas for my other story and I was struggling to make it flow, so I wrote this in the meantime. Tear it apart.
It was night. The gull tilted its wings into the warm updrafts and soared across the raging expanse of ocean. The chill salt water lashed and sprayed around him and he felt the strong winds bearing him up with wraithlike arms as surveyed the scene around him. To his east and west lay the irregular spits of land, Punta Sabbioni and the Lido thrusting outwards into the sea like intruding fingers while the islands surrounding them squatted awkwardly, hazy and dull in the darkness. Through the gaps between the straights the gull glimpsed a hulking mass lurking on the horizon and angled his wings slightly, swiftly changing direction. This was where the gull was headed.
He flexed his wings experimentally, feeling the power of the eddies and gusts that danced beneath them as Punta Sabbioni came into full view and lights of every colour glimmered brightly in the blackness turning the land below into a vast, flat Christmas tree. In the past the point had had been used as a port offering ferries down to the multitude of islands in the area but that had long since died out. The sea level had risen dramatically, reclaiming the ports rendering the business useless so the land had been scoured of car parks and terminals and in their place a large pleasure complex had been built above the water. Now the queues were no longer for boats but for slick shiny new bars and nightclubs where the young and carefree drank and danced the night away.
As the point swept beneath him, the gull studied the throbbing mass of people and buildings, the nightlife flashing before his eyes. A young Italian man took a long, heady drag of a cigarette while waiters carrying rounds of drinks to the party makers sweated under the heat of the summer night as a tacky neon sign flashed atop a bar “new restaurant for 2068.” A teenage girl stumbled around in a drunken stupor her eyes wild and hair lank whilst a huddle of security guards surveyed her from a distance.
Suddenly the earth fell away back into dark salty silence of white tipped waves, the shouts and bays of the raucous youth just a whisper on the wind as out of the darkness loomed the great island the bird was headed for. From the faint light of the moon the outlines of the buildings ahead and the black waves below were tipped in silver foil which shimmered wetly on the water. The island was much closer now and the seagull’s searching eyes could make out huge ornate palaces in the moonlight, a green topped basilica, rustic, brightly coloured houses with paint peeling after years of neglect. Smaller details began to sprig up one by one, shuttered windows, fallen lamppost, a great emerald coloured statue and hundreds of wooden poles poking out of the sea like an overgrown reef. Years ago, probably on a night very much like this one, Gondolas would have bobbed merrily next to the piers and the waterfront bustling with people, tourists snapping photos and young couples intoxicated by the atmosphere of the once romantic city. Moustachioed waiters would have poured exquisite house wine for throngs of holiday makers while elderly women gazed in wonder and flawless sculptures and stunning mosaics. Now the island city lay abandoned and empty, perpetually flooded by the sea. The quaint alleys and monolithic churches had become infested with eels and crabs, starfish plastered themselves to the undersides of arches and mussels clung to the corners of houses in grimy clumps. Venice had become a ghost town in the past 30 years, now only fit for the myriad of sea life.
Set back from the seafront, there stood two huge pillars, their bottom submerged in the salty brew. Before the town was flooded, the pillars had held two statues, a figure of Saint Teodoro of Amasea standing tall and proud on the back of a great sea monster, the other had held the magnificent winged lion of Saint Mark, its stony teeth bared and flinty eyes looking out across the plaza. Since the sea had reclaimed the island, both statues had long since disappeared, no one had any idea where they had went but the most popular theory was that of thieves stealing the statues and selling them on for millions.
The gull caught one last buffet of air and alighted on the rightmost pillar in a swoosh of feathers, surveying the vast courtyard that stretched before him. He shuffled uneasily. Hundreds of years ago, prisoners would have been tortured, burned, dragged screaming through the cobbled streets by horse and beheaded between the two columns under the watchful eyes of the saints. Despite its aesthetically beautiful appearance, the gull knew it was an evil place, steeped in centuries of blood and death. Under the eerie sheen of the pale moonlight it was almost believable that the spirits of the damned prisoners were crying out from beyond the grave. The gull’s uneasiness grew and spooked, he took off again, circling around the dilapidated town until a glint of silver caught his eye down in the harbour. A swarming shoal of fish.
The gull locked onto the mass, angled his black tipped wings and dived into the throbbing lump like a bullet, the air streaking past as he descended into the ocean. The water was slick to the bird’s feathers as he snapped and plunged at the shining darts of quicksilver that wove around his desperate nodding beak and swam teasingly around the bird’s clumsy waterborne mass. The fish suddenly scattered like windblown leaves. The gull looked around confused but then he saw he what the fish had swam from. Out of the dark waters came a flash of teeth, bloodshot crazed eyes and a bump of green scales roared underneath him as the gull scrambled out of the way and up into the cool Italian air, squawking with indignation and terror. The water slid lightly off his waterproofed wings as he beat his wings powerfully, catching the salty breeze and soared away, putting as much distance as possible between him and the strange island.
Your vocab is challenging, but not in the info-dump, I Want To Impress You kind of way. Instead, you provide just enough detail without distracting us from the plot. Great job. 
I'd consider revising that part and maybe expanding on it a bit. 
but you have some super skill, i know you can figure out some way.
you are