Warren Ritchie, 49, died after being struck in the chest by machinery while in the hold of a vessel berthed at the port.
His mother Helen Dungey, 68, said the family was struggling with the loss of a "caring and gentle man".
"He had been hit very hard by the break-up with his wife, it broke his heart, and he had spent a year wallowing, really," Ms Dungey said.
Unions have called for a review of health and safety at the Port of Lyttelton after Mr Ritchie's death and another death last month of contractor Bill Frost.
Mr Ritchie's late father Barry was also a waterfront worker, and he came from a long line of hard workers from the Lyttelton area, Ms Dungey said.
"After he'd decided to get back to work, he went casual at the port for a while and he'd just been full time for a few months. He'd got himself a room in Lyttelton and he was just getting on with things really."
Ms Dungey said she had heard only a little of what had occurred in the accident. She said workmates were with him immediately afterwards and he hadn't suffered.
"There'll be a big investigation. I believe it's case of being in the wrong place at the wrong time. I've been talking with the Maritime Union, the port's people and the health and safety ones. They've been all very good with the family."
Mr Ritchie was a seaman for some years but gave up the ships to settle with his wife and was a bakery worker based in Christchurch for a long time before recently returning to the Port of Lyttelton, his mother said.
"He was a good lad, a wonderful son. He has two sisters, Michelle and Donna. He had no children but he adored his four nieces and nephews. We really don't know what we'll do now."
Mr Ritchie's funeral will be on Friday at 10.30am at a service in the Lyttelton Top Club.
