[ Nagisa isn't laughing, but he's got a giant shit-eating grin plastered to his face while Rei flusters that isn't much better than if he were laughing. ]

It's okay, Rei-chan. You're forgiven for not worrying about me as much as you should have. [ But wait, alone at sea? ] Huh? Why would I be alone at sea? I know how to swim in the ocean.