泳者 is read as えいしゃ (eisha) and means a swimmer.
えいしゃ
eisha
すいえいしゃ
swimmer
ゆうえいしゃ
およぐ
to struggle through (a crowd)
およぎ
swimming
えいりょくにんてい
swimming ability certification
わかもの
young person
おうじゃ
champion
きしゃ
reporter
とうじしゃ
person concerned
りょうしゃ
pair
ようぎしゃ
suspect
ゆうけんしゃ
bigwig