The westbound record however proved to be more elusive and she and her sister ship “Lusitania” enjoyed a friendly rivalry in shaving minutes at a time from their crossings. The breakthrough for MAURETANIA came from an unexpected source following propeller damage caused by striking a submerged object. In February 1909 the vessel was dry docked and four bladed “sabre” type propellers were fitted to the outboard shafts in place of the three bladed “paddle” type  originally fitted (this modification was later carried out on the inboard shafts as well). The new propellers improved her performance and finally in September 1909 MAURETANIA became the champion in both directions with a westward run of four days,10 hours and 51 minutes to give an average speed of 26.06 knots. From this day on the vessel reigned supreme upon the North Atlantic building up a well deserved reputation for reliability and punctuality. In the three years up to 1911 MAURETANIA made eighty-eight crossings without a hitch at an average speed of over 25 knots.