The 28-year-old is taking a six-month enhancement course which, if all goes to plan, will prepare him for work in the classroom by September 2005.
In the past Mr Ellis, who is from Plymouth and studying at Keele university in Staffordshire, has worked as a commercial diver and a civil engineer. He has also dabbled in property development.
He said he was attracted by the stability and security which a career in teaching could offer him.
"I used to spend my time immersed in muddy water at zero visibility, sorting out dams or pulling vans out of rivers - all the sorts of messy jobs that most people would never want to do," he said.
"And for a while I laid fibre-optic cables and inspected bridges.
"I can certainly earn a lot more money in other jobs - but this isn't about money.
"I'm expecting to earn about half as much when I start work as a teacher, but that doesn't particularly bother me.
"Sometimes when you are self-employed you can work for days on end but then not have anything to do for weeks. The work is spread out.
"I was really attracted to the whole environment of teaching - doing a job which is rewarding, where I can impart knowledge to others and have some stability in my life.
"I can certainly see myself staying in teaching much longer than I have in any other job."