Lucid Time!

I can't recall exactly the setup or motivations of the characters, but this is some kind of training or test to become an action hero. Today's lesson: blowing up a shark. Yes. A live one.
The setting is this lake. But there are these modular plastic platforms placed out on it that make a swimming pool like area. There is another smaller pool with a huge shark in it. The instructor, a middle aged man who's black hair I recall vividly for some reason, tells me to get in. He then gives me what I need for the mission. One Katana and one block of C4.
Then he releases the shark into the main pool and tells me to go. I take a deep breath and dive underwater. The shark has been starved so it swims straight toward me. I remember my training and that I am actually supposed to swim toward the shark and time it so that I go in without getting injured by the teeth.
I swim forward, very quickly and manage to shoot right into the shark's open mouth. The jaws close behind me and I am sucked down into the stomach. The stomach is a weird place. It's hot and there is actually an air pocket, but it doesn't seem like I can breathe the air. I still have the block of C4 in one hand. I feel for the button to arm it (it was dark in there. The only light was from an LED on the side of the explosive.) When I press the button I see 15 seconds come up on the screen.
Now for the hard part. I have to cut out of the shark. I remember in training when you do this, Ideally you want to do it from the side. I try to figure out based on how I am oriented what the side of the shark is. I cut through and see water starts coming in. Good, that means my blade went all the way to the outside. I make a wide cut, about 3 feet and then abandon the sword and squeeze through. This was by far the hardest part to do. But eventually I managed to push through back into the water.
There is a big cloud of blood in the water. But how often is it the shark's blood that makes the big cloud? When I think about it, the shark already looked dead at this point. I swim up to the surface gasping for breath.
After one deep breath- Ker-Blam goes the shark. A big plume of water shoots up behind me. I take a couple more breaths and the instructor says that I get a passing grade on this test. I ask the instructor about killing sharks. He tells me that the sharks are grown from clones and are mindless and cannot feel pain. This doesn't make me feel much better about it though.

I am now swimming in the lake outside of the pool area with a couple friends. The instructor is there too. He tells me about this skinny blonde kid who was his last student and actually died doing the shark test. Apparently he forgot the part about swimming toward the shark and getting past its teeth.