Pay attention Nicholas ..........
Quick Summary:
It's only a rulebook - no box.
Very similar to "Legends of the Old West" also produced by GW.
Basically it is a mix of Mordehim and LotR. A skirmish game between warbands and your heroes have the special moves and might points etc.
High Seas has the bonus of some boats v boats fighting, and fighting on boats action.
Now look for the Ships thread also on this board ....................