Hockley Brook
From there , its waters flow , via the Trent , to the Humber Estuary and the North Sea . 
<triplet> the Trent <subj> Humber Estuary <obj> mouth of the watercourse <triplet> Humber Estuary <subj> the Trent <obj> tributary <subj> North Sea <obj> mouth of the watercourse <triplet> North Sea <subj> Humber Estuary <obj> tributary