The official website for the previously announced upcoming Grand Blue TV anime has announced cast members. The anime is slated for this summer.

Cast
Iori Kitahara: Yuuma Uchida (Tokyo Ghoul:re)
Kouhei Imamura: Ryouhei Kimura (Nil Admirari no Tenbin)
Shinji Tokita: Hiroki Yasumoto (Megalo Box)
Ryuujirou Kotobuki: Katsuyuki Konishi (Kakuriyo no Yadomeshi)
Chisa Kotegawa: Chika Anzai (Kokkoku)
Nanaka Kotegawa: Maaya Uchida (the High School DxD series)
Azusa Hamaoka: Toa Yukinari (the Berserk series)
Aina Yoshiwara: Kana Asumi (the Yama no Susume series)

Source: Moca News