A capital ship at 15000 yards is about half the size of a 5p piece held at arm's length. In the twenty seconds or so for a shell to travel that distance, the ship moves around about one hull-length.
Factor in a rolling and pitching platform, smoke, atmospheric clarity (or the lack of it), optical estimates of range, bearing and speed...it's maybe no wonder "Agincourt fired 144 twelve-inch shells and 111 six-inch shells during the battle [of Jutland], although she is not known to have hit anything."
Andy