Noting the bbc news article . . .

According to a recent report from the UN Environment Programme, sea level is rising in the Pacific around the Marshall's at a much higher rate than elsewhere in the world. The rate of rise between 1993 and 2009 was 12mm per year, compared with the global average of 3.2mm.

The increase at this latitude is likely to be less than the average due to centrifugal force 'throwing' the sea out at the equator more. However there is island tilt due to isostatic rebound. The release of weight from more northern parts of the UK means the southern coast is sinking, that is the earth's crust at this point will sink a little into the mantle.

This has been calculated for Essex at approx 6mm/y, nearly double the global average.

At such a rate the high-tide boundary would be some 6cm (4¾") higher than when we bought the land.

NERC