[OSM-dev] oceantiles.dat false positives

[OJW]

Just been trying to use the oceantiles.dat file for selecting images to delete 
from the tiles at home server (due to those images being ocean)

Have I incorrectly parsed the file?  Amongst the first 20 or so results are 
tiles like these:

http://dev.openstreetmap.org/~ojw/Browse/?z=12&x=2235&y=955

http://dev.openstreetmap.org/~ojw/Browse/?z=12&x=1123&y=955

http://dev.openstreetmap.org/~ojw/Browse/?z=12&x=2267&y=936