The defenders could expect to enjoy several advantages. As they would not need to manoeuvre under sail, most of the ships' crews could man the guns. If properly prepared, the ships would have "springs"; extra cables bound to the anchor cables, which they could haul in or let out to veer the ship to bring its guns to bear over a wide arc. If close to a naval establishment (such as at the Battle of Copenhagen), they could rely on boats from the shore to bring extra ammunition or replacements for casualties and if in range the defending ships could be aided by coastal gun batteries. The worst British naval reverse of the Napoleonic wars occurred during an attack on a protected anchorage at the Battle of Grand Port.