This park is a national park, and used to render with a nice little dotted line around the edge. Now it is just a solid green area. In one of the comments on #1141 there is an earlier screenshot of how it used to look. Map location.
It looks like a recent change added the park tag to the relation, but still, the ocean should have a higher precedence than the green of a park, right?
Additionally, the park within a park is also greening out everything else.

leisure=park is not for national parks. See http://wiki.openstreetmap.org/wiki/Tag:leisure=park
It is for things like
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leisure=park is not for national parks. See http://wiki.openstreetmap.org/wiki/Tag:leisure=park
It is for things like

see http://www.openstreetmap.org/note/609461