But his friends and family are baffled by the suicide because the rugby-playing sixth-former

His friends said he was coping with everything

PC Mark Uprichard

was a gifted student with a mature approach to his studies.

An inquest at Cardiff Coroner's Court heard that the teenager - described as a popular student with no real problems - died without knowing he had gained three grade As and one grade B at AS level.

South Wales Police constable Mark Upritchard, who was called to the scene after the teenager's red Hyundai car was found at the bottom of the cliffs, said Mark had been out with his friends the night before.

He said all his friends said he had "seemed his usual self" and was "enjoying a night out".

Pc Upritchard told the court: "He was suffering from a rugby injury and was at a fairly important stage of his academic career.

Mark gained ten GCSEs at Bryntirion school in addition to his AS levels

"None of these was causing him a massive amount of problems.

"His friends said he was coping with everything."

Mr Smith had been working hard for his AS Levels and his father told the inquest that his son had achieved the 3As and a B in geography, English, information technology and business studies.

He was reported to have been deputy head boy at Bryntirion Comprehensive in Bridgend, and a member of Penybont Lifeguard Club at Ogmore-by-Sea, winning the junior British championships at sprint swimming when just 15.

His father told the inquest: "He had a very mature attitude towards his studies. He had worked hard."

"We can offer no explanation."

I don't think we will ever know what reason caused him to carry out this act

Dr Lawrence Addicott, Coroner

Mark's elder sister Lucy said on the night of his death she came home to find the front door open and a note in her brother's bedroom.

Their parents, Philip and Linda, were on holiday in Florida at the time.

Just a month before his sister said they had discussed a similar incident at Southerndown involving a 21-year-old man.

She said: "He agreed that Lloyd had everything to live for."

Coroner Dr Lawrence Addicott recorded a verdict of suicide.

"I don't think we will ever know what reason caused him to carry out this act," he said.