Freja gestured at the harvesters, who were glancing around them nervously, as if expecting the ocean to suddenly erupt with dangers now that they had left the barrier.
“The thing is,” she continued, “our bodies are used to a certain depth. We aren’t conditioned for the shallows up above. Going too high often leads to light-headedness. And we also aren’t used to the true depths. The pressure down there can do funny things to both body and mind. It is possible to develop that conditioning, though. That’s where acclimatization training comes in. You’ll stand a better chance in your test if you have some experience with heights and depths.”
“So why is the spot we’re going particularly good for the training?” Merletta asked.
“You’ll see,” said Freja, with the hint of a smile.
And when they reached the wild oysters, Merletta did see. The oysters were perched on a rocky shelf some distance above where the group had been swimming. Above them, the water was clear and unobstructed all the way to the surface high above. Below, the rocky ocean floor gave way to one of the steepest drop offs Merletta had ever seen. The bottom wasn’t visible, the vertical shelf disappearing into blackness.
The harvesters headed straight up to the oysters to begin their work. Merletta followed, watching in awe as one of the mermaids extracted a stunning pearl.
“This one’s a beauty,” the harvester commented, holding it up. The others clustered around to have a look, nodding.
“It’s not very round,” Merletta pointed out.
The mermaid chuckled as she stowed it safely in her satchel. “That just gives it extra value. It’s how you can tell it’s natural, not from a farm.”
“Trainee.”
The call brought Merletta’s attention back to Freja, and she hurried to rejoin the patrol. The older mermaid sent the other guards to sentry positions around the harvesters, then turned to Merletta.
“We’ll start with the height training, I think. Proceed up toward the surface until you begin to feel discomfort, then come back down. I want to test your natural limits to establish a base line.”
“What if I don’t feel uncomfortable at all?” Merletta asked.
Freja raised an eyebrow, but she looked more amused than disapproving. “Confident, aren’t you?”
Merletta shrugged. “Just asking.”
“Then you can go all the way up. Don’t actually break the surface, though, or I’ll be in trouble with the program for endangering a trainee.”
Merletta nodded, then turned upward. It was strange to be swimming for the surface with an audience of official Center guards rather than in secrecy. They were deep under the water line, and it took her a couple of minutes to swim up to where the shafts of sunlight were piercing the water. She reached up a hand, a suffocating feeling coming over her at being so close to the air but not allowed to enter it. But she knew she was already taking a risk in so openly displaying her comfort in the uppermost layer of water. She wasn’t about to disobey her instructions as well.
She swam back down, trying to pay attention to how the depth affected her body. She was so used to going up and down from the surface that she didn’t generally notice it. But now that she was focused on it, she noted the sensation of building pressure in her head. It wasn’t pleasant.
She reached the oysters again to find Freja staring at her. “Did you go all the way up on your first try? I told you to turn around when it became uncomfortable, and take it by degrees.”
Merletta shrugged. “I didn’t find it uncomfortable. If anything, it was more uncomfortable descending again.”
Freja narrowed her eyes thoughtfully, and Merletta’s heart picked up speed. Perhaps she shouldn’t have been so honest. But the older mermaid sounded more surprised than suspicious.
“Well, I don’t know when I’ve seen a stronger natural aptitude. We won’t waste much time on height training, then. Let’s see how you fare in the depths.” She jerked her head toward Felix, and he swam over. Merletta noted that he was the youngest of the group except for her, probably not much older than thirty.
“I’ll come with you,” he said kindly. “Swimming into a drop off is pretty unnerving the first time, plus there could be some dangerous creatures in there.”
Merletta nodded gratefully, not at all sorry to have company when venturing into the dark hole. She was determined not to show any fear, however, and she swam forward without waiting for him to go first.
“Turn back when your head begins to ache,” Freja called after them. “Unless you’re impervious to depth as well as height, of course.”
But Merletta very soon realized that she was anything but impervious to depth. She hadn’t gone far at all when the pressure became uncomfortable, and she had barely entered the dark part of the drop off when the discomfort turned to pain. She pulled up.
“We’ll go back up for a break,” Felix said, his voice reassuring. “You did well for a first time.”
Merletta didn’t tell him that she’d explored drop offs before now. She’d never liked going deep, but she hadn’t previously attempted it so soon after ascending to the surface. Clearly her body didn’t like the change in pressure any more than the next mermaid’s.
Determined to improve, she went down again, and again, shivering with the increased cold, and fighting against the suffocating feeling of the darkness closing around her. The harvesters worked for several hours, by the end of which time she’d barely managed to reduce the discomfort at all. Freja assured her this was normal, but Merletta still felt a little discouraged.
Any time she needed a break from the repeated descent, she was set to sparring with the other guards at varying heights. She was pleased to find no noticeable difference in her strength or endurance, even when she fought Felix a mere two feet below the surface. On instructions from Freja, she collected increasingly large rocks from the shelf just below the oysters and carried them almost to the water line above. Her arms ached after half a dozen such exercises, but she was able to complete the task without serious strain.