In addition, longtime recurring cast members Dennis Chun, Kimee Balmilero, and Taylor Wily were promoted to series regulars, while another longtime recurring cast member Ian Anthony Dale joined as a series regular and appeared in episodes seven through twenty.

McGarrett and Danny recruit lifeguard and former police candidate Tani Rey (Meaghan Rath) to join the task force to assist them but she is reluctant to do so.

After picking up Adam (Ian Anthony Dale) from the airport, McGarrett receives a call from Junior about a bank robbery in progress.

Adam, Junior, and Steve then enter the bank and learn that the criminals escaped through a tunneled out hole in the safe.

McGarrett, Danny, Tani and Junior discover a yacht abandoned at sea and find 11 dead bodies.

Adam, Grover and Jerry have only 8 hours to track down the people responsible and find an antidote to save the team.

Kim and Park had been seeking pay equality with co-stars Alex O'Loughlin and Scott Caan, but did not reach satisfactory deals with CBS Television Studios.

[43] Following Kim's and Park's departures it was announced that longtime recurring cast member Ian Anthony Dale who portrays Kono Kalakaua's husband Adam Noshimuri had been upped to series regular for the eighth season.

[44] On July 21, 2017, it was announced that recurring cast members Taylor Wily, Kimee Balmilero, and Dennis Chun would also be upped to series regulars for the eighth season.

[45] On September 28, 2017 in an interview with executive producer Peter Lenkov he was asked if Christine Lahti had a chance in returning during the season.

[48][49] It was later announced on March 19, 2018 that previous main cast member Michelle Borth would return as a guest star in the season's twentieth episode.