Warusam and a 13-year-old boy had been attempting to swim ashore after their dinghy broke down.
After an extensive search, Warusam’s body was found with injuries police believe to be “consistent with a crocodile attack”.
His mother, Kemana Kusu, described her son as a kind-hearted and curious young boy.
“Baidham was a very athletic person whom participated in all events whether it was in school or his local footy club the Edmonton Storms,” she wrote in a GoFundMe post.
“Always smiling and eager to help anyone who crossed his path. A person who was very observant and would always strike a look of curiosity.”
“In this time of difficulty as we all know one is not prepared to face life’s sudden tragedies,” she wrote.
“I am humbly seeking assistance in aide to help my children and I endeavor through this difficult time.”
Saibai Island is a low-lying island four kilometres from Papua New Guinea’s mainland and about 900km from Cairns in Far North Queensland.
The Department of Environment, Science and Innovation (DESI) located and “humanely euthanised” the crocodile on Saturday, in line with the wishes of the Saibai Island community.
“DESI has given their condolences to the family and friends of the teenager,” the department said in a statement.