Day five of sea search fails to find men

A fifth day of searching has failed to find two men, presumed dead, after a fatal boat trip southeast of Hobart.

Police and volunteers took to the seas on Thursday while trail bikes scoured coastline looking for a 26-year-old Hobart man and a New Zealander aged 35.

The pair were among a group of four mates aboard a runabout which launched from a beach at Cremorne on Sunday and failed to return.

The bodies of Magnus Julian Ritter, 34 and Luke William Davies, 32, were found 3km apart in Frederick Henry Bay on Monday.

There has been no sign of their companions, nor the 4.9-metre fibreglass boat.

Water police inspector Lee Renshaw said the search will continue.

"Tomorrow's operation will involve police vessels searching areas previously searched in Frederick Henry Bay, including Norfolk Bay, the area north of Lime Bay State Reserve into the Seven Mile Beach area near Tiger Head Bay and the area around Sloping Main."

A helicopter used in past days has been stood down, with no debris spotted since a fuel tank, tackle box and life jacket were found on Monday.

While the search continues, personal trainer Mr Ritter's mother Sabine Wagner has paid an emotional tribute on social media.

"Losing your child, is your worst nightmare come true," she wrote, as reported by News Corp.

"While my heart will be broken forever, I am so proud to know that Magnus had such a positive impact on so many people.

"He certainly was one in a million, cheeky, funny, smart, beautiful and a fighter."

All four men were linked to the University of Tasmania, either as staff or students and support is being offered to those who need it.