Rene Levi drowned in the Mersey River at Bells Parade when he was 15 years old.

An inquest was held into his death in October last year in Devonport and in December in Launceston.

Coroner Rod Chandler heard from classmates, family, teachers, emergency services personnel and education department employees.

On November 16, four grade 9 classes from Latrobe High went to the popular recreational area for an outdoor excursion.

They were accompanied by three physical education teachers, a relief teacher and a student teacher.

Rene was one of four boys who decided to swim in the river while the rest of the students participated in land based activities.

During the inquest, it was revealed that significant rain set in and the excursion turned ``chaotic''.

The group went back to school between noon and 12.30pm. No roll call was conducted before the group left Bells Parade and there was no head count of students who got into the water and back out.

Teacher, Stephanie Jackson, told the coroner she picked up Rene's shoes from the riverbank and took them back to school where she left them at the front office and asked staff members to give them to him if he came looking for them.

That was several hours before Rene was even considered missing.

During a kayaking lesson about 3pm, the senior physical education teacher, Tim Jolly, found Rene's body fully submerged and face-up in the river.

During his submissions in December, counsel assisting the coroner, Chris Dockray, said the absence of a risk management assessment for swimming activities on the day pointed to a serious failure on the part of the school and teachers.

He told Mr Chandler that ``ignorance'' seemed to be an excuse for the immense oversight from the top down.

``The Department of Education failed to ensure teachers, including Latrobe High School principal Phil McKenzie, understood the outdoor education guidelines,'' Mr Dockray said.

Mr Chandler will hand down his findings tomorrow in Devonport.