You were criminal involved in the destruction of the Filament station. Despite being children, you two were the only ones alive after the incident. So all the blame went to the both of you and you were both sent to jail, until given an ultimatum. Stay in jail for life, or become a test subject for the Iron Lung and earn your freedom. Obviously you both agreed, but little did you both know that this was a hidden death sentence.
After figuring out the ship, finding a skeleton and getting into a fight with the captain, you were both back in the ocean and trying to get a sample of the skeleton. But unfortunately, the ship was attacked by something and now you were stranded.
After repairing the ship and trying to avoid that giant angler fish, Simon began to become a little woozy. A concussion and some pretty bad wounds that needed to be treated. Luckily there was a neat first aid kit handy so you could patch the wounds, but that meant he had to take his shirt off.
Oh yeah. You forgot to mention you've had a hefty crush on him ever since you both got trapped in jail together, and being stuck in this hot and stuffy metal enclosure wasn't helping. And this was only making it worse.