Leslie, I don't think that ships came up to Warkworth, I wouldn't have thought there was ever enough depth, even at high tide. Early references to shipping seem to have the names of Amble and Warkworth as interchangeable, probably because Amble was part of Warkworth parish.
I would guess that the officials responsible for dealing with shipping would live in Warkworth, for preference, as Amble was a pretty basic place (no comments please
) and would have a mooring for boats so that they either went down to the mouth of the river or people came up when shipping moored.
I've never heard reference made to the discovery of jetty foundations or such by the Butts, but somebody else might have.
I have one Warkworth ancestor who married a customs official....he was based in Warkworth for a while, with an extensive "ride" but was moved around the northern region. They did keep a property in Warkworth though.