"You shouldn't be grabbing people's ankles and dragging them down to begin with," he only continued.

"The point of this excursion is for everyone to enjoy themselves and this would only make the younger aged visitors afraid of getting in the water."

Perhaps not, but at this point he was just annoyed and it technically a valid reason.

"Not to mention the risk of you accidentally pulling someone who may react badly and end up drowning."

Now this was a more plausible reason. But regardless—

"Your so called 'shark days' are over, Kanji."