[He gives her a confused look when she asks why he wouldn't want her going out there alone, wondering if he's really been that shitty recently to her that she has to ask.]

It's not dangerous, but if you're worried about something happening, then maybe something is going on.

[He believes her when she's so confident about it, he'd never insist otherwise.]

So I don't want you going somewhere maybe dangerous. If there's something going on with the water, what's the harm in having me there for backup? I mean, I do have fairly okay skills and sometimes, they even come in handy.