What a 1948 Vanguard gives Jellicoe in 1915

Who would control a 1948 HMS Vanguard appearing at Scapa Flow in 1915, and what difference would she make?

Jellicoe would take her, and her radar-directed 15-inch fire could make the Grand Fleet overwhelmingly effective.

A Vanguard appearing at Scapa Flow in 1915 falls under Jellicoe's command rather than Beatty's. British radio specialists such as Somerville provide a plausible route to understanding and maintaining her radar even if replacement production remains impossible. Radar-directed fire control combined with modernized 15-inch guns would let the Grand Fleet detect and engage the High Seas Fleet under conditions the Germans could not match. The ship would still require careful husbanding because its advanced components could not be readily replaced. Even so, at Jutland its information and gunnery advantage could turn a British victory into the destruction of much of the German battle fleet.