At least she grabs him by the shirt and nothing else, so he doesn't mistake her for something less friendly. He's still in that dazzled space between extreme pain and oxygen deprivation when she releases him, but the force of the struggle next to him snaps him out of it properly. He gasps in air when he breaks the water's surface, feeling lightheaded from a great unpleasant combination of factors - he can hold his breath for ages, when he's not being chewed on. No such luck at present.

But then he doesn't see his rescuer, and so he takes a proper breath this time and sinks back into the water. Can't be helped. At least his eyes have adjusted to being able to make out shadowy figures in the barely-helpful moonlight - hopefully Sonja is just looking for him, and not being eaten. He sees her and reaches out with his functioning arm (blade held curved backwards, of course), because there's no use in them getting tossed further apart in the chaotic water.