In 1969 Arethusa together with Juno, Hampshire and RFA Lyness visited Barbados, transited the Panama Canal and proceeded to Callao in Peru, Valparaiso, the Falkland Islands and Montevideo returning to the UK for Easter.

She continued to Cartagena, Dominica, St Martin, Bequia, Georgetown, Belize, Fort Lauderdale arriving in Portsmouth in April 1970.

In 1972, Arethusa undertook a further Beira Patrol which was designed to prevent oil reaching the landlocked country of Rhodesia via the then-Portuguese colony of Mozambique.

In 1973 Arethusa began her modernisation which included the removal of her one twin 4.5-in gun, with the Ikara anti-submarine warfare missile system taking its place.

In that same year, Arethusa, like many Leanders, took part in the Royal Navy's Fleet Review in celebration of HM the Queen's Silver Jubilee.