But when the 2004 Summer Olympics commence in Greece in August, they will put friendship aside for a brief time.
Stewart is a member of the Canadian women's synchro team and Grimshaw represents Great Britain (through having British-born parents).
They qualified after stellar performance in the pool at a recent Olympic qualifier in Athens.
As the youngest member of the 12-member Canadian contingent, Stewart, 18, helped Canada earn a fifth-place finish in the team qualifier.
The top eight teams qualified.
Currently residing in Huntington Beach, Calif., Stewart was also selected to compete for Canada along with teammate Fanny Letourneau, 24, in duet.
The swimmers, who are in their second year of competing and were silver medallists at last year's Pan-American Games, were fifth.
The top 24 duet teams qualified for the Olympics.
A 20-year-old sophomore attending Ohio State University and a member of its synchronized swim team, Grimshaw competed in the duet with school teammate Chelsea Luker of Montreal and finished 21st.