Haunt me in my sleep
You have no intent of drowning or harming, only proving a point, helping her understand how to move in the sea. Her blows land squarely enough on your stomach, eliciting a mild oof but doing little real damage given the impact of the water. By then you've already released her, anyway, again bouncing back on nimble feet and giving her space to rise up above the surface, time to catch her breath.
"That was good - ya held steady - but instead'a fightin' with yer fists, y'gotta make use'a what you got. The water, an' how it changes weight." Very Yoda, you insufferable old goat. "Here, yer turn t'come at me. I'll show ya what I mean." Squaring your feet on the shifting bottom (and swaying as a wave presses against your shoulders) you wait for the little firebrand to strike, anticipating a retaliatory blow similar to your own.
Sinking in my sea
