Missing/inconsistent River Thames map data in Overpass Turbo

Question

I have noticed the River Thames cut off quite abruptly when applying the following query to Overpass:

(
  way["natural"="water"]({{bbox}});
);

out body;
>;
out skel qt;

The resulting data is shown below - you can clearly see that the background map shows the river continuing, but the data does not follow that:

I've tried all the water types I can think of (below), but the best I get is a single line that follows the centre of the river, and not an area polygon that is topologically accurate.

(
  way["natural"="water"]({{bbox}});
  way["natural"="coastline"]({{bbox}});
  way["waterway"]({{bbox}});
  way["water"]({{bbox}});
);

out body;
>;
out skel qt;

EDIT: This is the result of AndreJ's answer:

relation(2263653);>>;
out skel;

Answer 1

The river Thames is too large to digitize it in one single Openstreetmap way element.

Therefore, a relation is created to group all riverbanks belonging to it.

You can query that relation directly with Overpass Turbo, with no need to enter a bbox:

relation(2263653);>>;
out skel;

You can look up the relation ID for UK rivers at http://wiki.openstreetmap.org/wiki/UK_Waterway_Relations following the links given there.

---

Update

The riverbank multipolygons are not included in the River Thames relation. Unfortunately, the multipolygons have no tags, the outer lines have waterway=riverbank, but the inner rings have other or no tags. You can get the correct riverbank only if you put all data of a larger bbox (or South England at least) into a Postgis database to sort that out.