Pearce (acting as Station Commander while Mick takes time out to be with his family) organises a day trip to Southend for Blue Watch and their families.
The relief come across a beached whale and try to save its life.
The complicated relationships between Sally, Mick, Shauna and Mooney come to a head as Shauna confesses to Mick that she had slept with Mooney while he was out with their son and Sally tells Mick she has feelings for him.
Mick decides to deny his true feelings in both instances, telling Shauna he doesn't believe she betrayed him and lying to Sally telling her he was unaware she had feeling for him.
Mick's actions cause Sally to once again be charmed and seduced by Mooney.