The sunken ghost ship

An odd lemur-like being swims on the ocean's surface, with an air tank on his back and goggles on his forehead, and nothing else, his cock hanging out as he didn't bother to find swimwear, knowing no one will see them. They, a winged lemur named Momo, were out here looking for a particular shipwreck they'd been directed to... Well, it had been more of a dare.
Earlier that day, Momo had shown off his new scuba gear to his friend Appa, a sky bison. "I can finally explore underwater without needing to go up every few minutes!"
"Good for you! And I know just the place for you to really break it in... There's a shipwreck not far off the coast, it'd be perfect!"
"Oh, perfect! I'll head down there first!"
"Of course, if you're gonna go there, I should tell you... There's a rumor it's haunted."
"W-wait, haunted? O-okay, maybe not there then..."
"Ah, it'll be fine, you can handle it. Or are you too scared?~"
"I-I'm not scared, and I'll prove it! I'll go to that wreck, and I'll bring you something back to prove I went!"
And, that was how Momo had ended up out here. While he certainly wouldn't admit it to Appa, he was scared again, wondering if it was actually true that the wreck was haunted... Eventually, he can see it below him, and he stops to lower his goggles over his eyes and take some deep breaths to try to calm himself down.
After a couple minutes, Momo calms enough that he's willing to get started. Putting the regulator in his mouth, he takes an experimental breath to make sure the tank's working. With his lungs filling, he finally dives under, starting to swim down to the foreboding wreck deep below him... Eventually, he reaches it, sinking down to the deck and looking around a bit nervously. The only air around is what's in his tank and the bubbles he exhales, but drowning isn't what concerns him; what if the ghost here is real, and it finds him? He can't just leave though, or Appa will know he chickened out...
Deciding to just make this trip quick, Momo hops off the deck and starts swimming, soon finding a way into the ship proper. Despite the lack of any notable aquatic life, the interior is ominous, the sunlight having trouble illuminating it. The winged lemur feels extremely out of place here, but without any potential ghost immediately making itself known, he starts to slowly feel better. Cautiously exploring, and making sure not to press on anything too hard for fear of it collapsing, Momo decides to actually look for something impressive to show Appa instead of any random thing.
About 15 minutes of exploring later, he's perfectly calm again, all but certain the ship isn't actually haunted... Then, a chill passes by him, and the fear immediately returns. While Momo does manage to convince himself it was just a weird current, maybe made by a passing fish he didn't see, he starts wanting to leave again. Now being at pretty much the wreck's deepest point, he finds the perfect trophy to show Appa: A tattered flag!
Holding the flag in one hand, Momo starts heading back the way he came, but is stopped by something grabbing his paw! He yelps and looks back... It's just a strap. It's pretty thoroughly wrapped there, but he sighs in relief that it's not something worse, and gets to work on freeing himself. While it's stubborn and keeps sliding back into place, sometimes tickling a tiny bit, he does eventually get it off. The chill from earlier briefly comes back after that, but Momo does his best to ignore it this time, knowing it doesn't mean anything.
Checking the gauge on his air tank to see he still has plenty of time, and not afraid any more, he decides to try out something he never had before: Masturbating underwater. Setting the flag down and slowly kicking to stay in place, Momo starts jacking off. It doesn't really feel any better than normal, but it definitely does feel good, and he moans a little into his regulator. A few minutes later, as he gets close to an orgasm, he speeds up to get himself to the point of no return and as far past it as possible before his orgasm really starts, tensing up and curling his toes.
It seems being underwater might be helping his pleasure after all, as Momo has a powerful orgasm, moaning bubbles and splaying out his toes, even the regulator falling from his mouth as cum is unloaded into the water. He comes down from his climax after about 10 seconds and happily sighs, the bubbling reminding him inhaling right now wouldn't go well. Quickly grabbing the regulator and shoving it back in his mouth, Momo inhales again, grabs the flag, and starts making his way out of the wreck.
Halfway back out, the chill returns once more, and it seems to stay with him this time. Not really minding it any more, he just keeps on swimming, eventually getting to the exit. He looks at the flag and smiles, proud of having gotten it despite his initial fear, and starts heading for the surface-
Before being stopped again, both of Momo's paws feeling like they're being held. He looks down, ready to need to untangle himself again... But there's nothing there. Nothing is visibly holding him, but he can't meaningfully move his paws, just wiggling his toes around... There really is a ghost! His eyes go wide in fear, and he drops the flag as he frantically tries to get loose, but he can't really get away from what seems to just be force surrounding his paws.
During his struggles, the ghost starts pulling him back into the ship, and he's powerless to stop them. Then, once he's back inside, he feels a tug on his regulator! Knowing what's about to happen, Momo just barely manages to get a deep breath before the regulator is pulled away, forcing him to hold his breath. He's briefly held still as even the air tank is taken off him, and he looks on in fear as it starts floating away from him. He can't surface from this depth on one breath!
Being released again, Momo immediately starts swimming after his air tank, bubbles starting to stream from its regulator, while the ghost also continues to toy with him directly. It seems to have a bit of a fascination with his paws, rubbing and poking at them, distracting him a little. He briefly looks back, and sees that a couple mostly-transparent hands have manifested and are doing the prodding. Trying his best to just ignore that, he looks ahead again just in time to see that his air tank is going into a room off to the side, and he follows after it.
This appears to have been a dining room, with several tables and quite a few overturned chairs that his air tank is now rolling among. As Momo continues to chase after it, tossing furniture aside and starting to feel a need to breathe, the ghost seems to start taking an interest in something else on him in addition to his paws. "Mm!" Momo bubbles in surprise as he feels the ghost start stroking his exposed cock, a third spectral hand appearing.
As his time spent holding his breath gets to 3 minutes, and the chasing and the tank's bubbling continue, he starts trying to swat the ghost's hands away. Of course, with those only being selectively physical, he can't do much. Except... He grabs his cock, covering it up, and the ghost isn't able to masturbate him any more! ...Then Momo's hand gets pulled away, and it just resumes. Admitting defeat in that regard, he tries to just ignore the pleasure.
Another minute, and he whines a little from his growing need to breathe. His breath holding record being 7 minutes, he doesn't have a whole lot longer... But the ghost seems to want a change of pace now, and the air tank rolls from the room - avoiding Momo, of course - and back into the hall. As he follows it though, the pleasure of the ongoing spectral handjob is getting hard to ignore, starting to get him close to an orgasm for a second time on this dive. The hands on his paws are continuing as well, giving them oddly gentle squeezes and weaving between his toes.
Following the air tank again, being brought deeper and deeper into the ship once again, Momo resists the pleasuring as best he can, but he just can't take it any more. Pausing his swimming, he clamps his hands over his mouth as he stretches out and moans, cumming for a second time. Thankfully he doesn't lose much air, his decision to cover his mouth having been a big help, and he forces himself to ignore the fading pleasure and keep swimming, catching up with his air tank.
Having gone 5 minutes without a fresh breath now, Momo's lungs are just beginning to burn, bubbles leaving his nostrils without him really being able to stop them. He and the air tank are back in the deepest part of the ship again, and the tank has resumed rolling around amid the room's clutter. Holding back a frustrated sigh, he continues trying to get the air tank, bubbles still pouring from its regulator as its air is wasted.
Time keeps on passing, and the air tank stays away from Momo, and while it finally stops bubbling, he's not sure whether that's for a good reason. The 6 minute mark comes, and he starts getting a purple tint on his face. As fruitless as it's been so far, he keeps trying to get the air tank, though he now has to cover his mouth and only swim with one hand.
Finally, Momo nears his limit, and he can't focus on swimming any more. As his face starts turning blue, he covers his mouth with both hands, sinking a little... Then he feels something bump against his paw. The air tank! The ghost is finally letting him breathe! He quickly scrambles for the regulator, shoving it into his mouth and sucking in... Nothing. That was why the bubbling had stopped: The tank is empty!
There's a distant disembodied giggle as Momo drop the regulator and covers his mouth again. He's successfully ignoring the rubbing on his paws now, but only because of the fierce burning in his lungs. The ghost has started masturbating him again as well, and even that is ignored... Then, the ghost decides to force its victim to pay attention to it.
A couple more ghost hands appear and grab Momo's wrists, pulling his hands away from his mouth! Bubbles stream from his lips as he frantically struggles, but he can't move his hands any more, just kicking around. With a futile attempt to cover his mouth by pressing it against his shoulder, his chest starts jolting back and forth, deflating and reinflating his cheeks as he reaches his limit.
Bubbles spurt from his lips and nostrils, until a cloud of bubbles bursts free as he finally exhales, almost immediately being followed by water rushing back in. Momo manages to swallow and stop the first attempt to inhale, but another follows, and another... Soon, he's chugging seawater, desperately trying to keep it from reaching his lungs as he squirms in the ghost's grip. His belly fills, and even expands some, noticeably bulging out his midsection, until his stomach is full and there's only one place for the water to go...
Unable to redirect the water any more, Momo's next attempted breath reaches his lungs! He coughs up the water, then gasps even harder than before, flooding his lungs and truly starting his drowning. Surprisingly, the ghost lets go of him at this point, letting him grab his neck and even leaving his paws and cock alone. It hardly helps Momo feel any better of course, as he gurgles painfully and chokes, rapidly sucking water in and out. He thrashes hard enough in his struggles that his goggles are knocked off, heavily blurring everything around him, but he hardly cares about that right now.
His paws bumping against the floor reminds him that just staying here drowning isn't going to help; as unlikely as his survival is at this point, he needs to get to the surface! Forcing himself to jump off the floor and start swimming, he... Sinks and lands on his face. All the water in him is weighing him down enough he can't swim! Although, unknown to him, that's only part of it; the ghost is adding to his weight as well, as simply being flooded wouldn't keep him from swimming.
Getting back up, and after doubling over and gagging for a moment, Momo starts to run as best as he can underwater, desperate to get out of the wreck as soon as possible. His choking echoes through the ship, but is only heard by himself and the ghost. Despite the situation, his cock is throbbing heavily, getting closer to an orgasm without any stimulation being necessary. And, partway through this last, frantic struggle, he reaches said orgasm, starting to leave a trail of cum behind him. Momo barely even notices, continuing to run through the ship's halls, having trouble finding his way due to losing his goggles.
After his first full minute of drowning, an especially hard cough forces up the last couple bubbles from his soaked lungs, leaving nothing but water in him, but it wasn't as if the air he had left was helping anyway. Dizziness is beginning to form in Momo's head, his face fully blue, and he stumbles a little as he's just starting to calm from the lack of oxygen. It certainly isn't getting easier to navigate the ship as his thoughts start to slow, but he can't give up, he needs to get outside and soon!
Another minute, and Momo's senses are dulled enough that he doesn't really feel like he's drowning any more. The choking has thankfully stopped, and he simply pants the water, occasionally hiccupping as his body tries to keep it out. He can't focus enough to run without tripping, so he just walks instead, feeling along the walls both to guide him and keep himself up. If he were more coherent, he'd be impressed with his endurance at being able to breathe water so long.
3 minutes of drowning. Momo's breathing has calmed further, but he's now having a bit of trouble staying awake. He needs to lean on a wall to keep from falling at this point, and his lidded, tired eyes are having even more trouble making anything out now. Stumbling along regardless, he gurgles a little as he slips some, just barely managing to stay up. Even now, he's fully erect, and while his cock throbs with his fading heartbeat, it's getting increasingly unlikely Momo will achieve yet another climax.
Eventually, the wall seems to go away, and he falls, landing on his back. At this point, he starts to consider just giving up, letting himself pass out... But, above him is something bright, and it feels important, but he's too drowned to think of what it might be. Momo's sluggish mind slows farther, his vision starting to fade...
Then, jolting back to awareness, he remembers what he's looking at: The surface! He's outside! With a pained gurgle, he scrambles to stand up and jump off the deck, frantically trying to swim up. But, he just sinks back to the deck again, still being weighed down by both the water and the ghost! Desperate and not really thinking clearly as his renewed strength starts quickly fading, Momo keeps trying, essentially just hopping up and down, flopping his dick around and jiggling his somewhat bloated belly.
Before too long, he can't keep up the struggle any more, and drops to his knees, taking shallow watery breaths. With an even greater lack of oxygen than before, even his cock and pawpads have a slight purple tint, his paws repeatedly clenching and unclenching as he clings to consciousness. Soon, he can't even do that any more, and falls onto his back again, starting up at the surface as his vision dims again. He hiccups and shudders a little as he barely feels some prodding at his paws again, the ghost having returned to messing with them. Momo's toes curl some at the sensation, before relaxing for the last time as he finally loses consciousness after about 4 minutes of drowning.
The ghost continues toying with his body for some time, especially his paws, as little twitches happen all over him. His cock stays fully erect and even still throbs, but it's quickly getting weaker and slower with his fading heartbeat. After a little while, it throbs a bit harder a few times, sending out one last tiny load... And, soon after that, the throbbing stops as Momo's overtaxed heart does. For a couple minutes after that, the ghost keeps messing with his paws, before seemingly getting bored at the lack of response and leaving him on the ship's deck, to remain until someone finds him... If that ever happened.