Light doesn't travel far underwater which meant that sight was the least likely sense to use to detect something. Instead, most deep sea creatures, submarines included, relied on their sonar and their ampule to detect the presents of other animals. The key was to remain as still as possible and that's exactly what Stingray did. She heard Orlando above her, hovering with her prop rotating steadily to combat the currant. Not moving, just listening.
The diesel submarine was an expert at playing possum and her location on the ocean floor meant that Orlando's sonar couldn't pick her up. The nuclear sub couldn't distinguish the ocean floor from her hull. Something fell on her head and Stingray stifled her hiss of pain, not even daring to look up and see what it was. So now she was dropping stuff on her hmm? Alright, if Orlando wanted to play dirty, Stingray could play dirty.
A few hours ago, she'd consumed an entire great white shark. A full meal for a submarine of her size and type. But there was one little problem, shark's blood had a nasty habit of reacting foully with the enzymes in a sub's stomach. The results were often, explosive. Stingray could feel it coming on, shutting her eyes tightly as the inevitable happened.
BBBBBBBBBBBBBBBBRRRRRRRRRRRRRRRRRRRRPPPPPHHHHHTTTT!
Orlando's head shot up at the sound and she looked around, trying to pinpoint its exact location. Then her nose started twitching. It was slow, gradual but Stingray like all submarines knew that while sight didn't travel far underwater, other senses including smell worked just fine. Orlando shuddered, wrinkling her nose as she tried in vein to hold her breath until the smell cleared. Water did an excellent job of absorbing the smells and carrying it around for all to sniff out. Stingray's fart would last a long time. Far longer than the Los Angeles-class' ability to hold her breath. Orlando gasped, daring to smell the water again and immediately put her fins over her nose with a noise of disgust.
Stingray was breathless from her silent laughter as the bigger sub left the area. "I should eat shark more often." She chortled.