They play their games at Safeco Field.
Third Base Dugout
In baseball the home team is in the first base dugout and the visiting team is in the third base dugout. So when the Devil Rays are playing at home they are in the first base dugout. When they are playing a road game, they are in the third base dugout.
The Rogers Centre.
Along the Third Base Line
I would say that it is a fair ball. When it goes into the dugout they call time.
Julio Cruz played in just one game at third base for the Seattle Mariners in 1982 and did not start. He made one putout, had 3 assists, and committed no errors, equivalent to 0 errors per game (estimate based on total games played in). He had no double plays.
Third base side
Munenori Kawasaki played in just one game at third base for the Seattle Mariners in 2012 and did not start. He played for a total of 3 outs, equivalent to .11 9-inning games. He made no putouts, had no assists, and committed no errors, equivalent to 0 errors per 9-inning game. He had no double plays.
Rich Amaral played in just one game at third base for the Seattle Mariners in 1997 and did not start. He played for a total of 3 outs, equivalent to .11 9-inning games. He made no putouts, had no assists, and committed no errors, equivalent to 0 errors per 9-inning game. He had no double plays.
Domingo Cedeno played in just one game at third base for the Seattle Mariners in 1999 and did not start. He played for a total of 6 outs, equivalent to .22 9-inning games. He made no putouts, had no assists, and committed no errors, equivalent to 0 errors per 9-inning game. He had no double plays.
Butch Huskey played in just one game at third base for the Seattle Mariners in 1999 and did not start. He played for a total of 3 outs, equivalent to .11 9-inning games. He made no putouts, had no assists, and committed no errors, equivalent to 0 errors per 9-inning game. He had no double plays.