It was a detail Donnie had neglected to consider. He'd gotten caught up in the moment. Once Jack had caught up, he looked over, concern wrinkling his brow.

"Easy, easy," he said, nudging his board closer to the pirate, reaching out to grasp him by the shoulder. "Slow breaths, don't panic." Maybe it wasn't panic, which was good, but it was better to keep Jack calm all the same. "Sorry, I got carried away- I should've accounted for the difference in atmospheric pressure. We should head lower, it'll be easier to breathe."