Members of Tua's family gave Navy volunteers their blessings as they joined local police efforts in the search for their son.
However, there is still no sign of him.
A spokesman for the NZ Defence Force confirmed several members of their staff had travelled to Samoa last week to help and offer support not only in the search but also to their colleague's extended family.
A family liaison officer was sent over specifically by the Royal NZ Navy, he said.
"This was to ensure the family were linked up with support from local authorities including the Samoan police - who are in charge of the search efforts - and the New Zealand High Commission.
"Last week, seven Devonport-based Navy personnel, who are friends of Joseph, took leave and travelled to Samoa privately to join in the search and provide support to Joseph's family."
All Navy personnel have since returned to New Zealand.
However, the family liaison officer is due to fly back to Samoa tomorrow.