Foster's eyes open, barely. Some of it is a matter of seawater collected in his lashes and on his lids, some of it is the sun high overhead, heat and light penetrating his vision even with his eyes closed. But most of it just... he's having a hard time emerging, entirely, and he forgets to pay attention when he speaks.

Pay attention to what?

The tide.

He opens his mouth, presumably to say something about his intentions in cosplaying his own corpse, but what that something is Amethyst will never know, because at that very moment the waves roll back in and Foster gets a mouth and nose full of seawater and debris, and that gets a reaction.

Mostly in the form of choking, and swallowing seawater, and choking some more as he spits whatever sand and sea he can, not quite retching as he regurgitates it back out of his throat.

If Amethyst is leaning over far enough, she'll get that mouthful of seawater sprayed in her face.