The best technicians are detail oriented, observant, curious, obsessive, organized, mechanical, tidy, and industrious. If you are reasonably good with most of these traits, likely you would be of use at your local dive shop (LDS) today.
At the LDS you would get an education on a wide variety of equipment and plenty of time doing light servicing, cleaning, and adjusting of equipment. You don't have to be factory or course certified to do many basic Tech Jobs - Like changing spooler o-rings in an HP gauge/Hose system.
If you enjoyed the work, and did a good job, you would know it. Don't forget the opportunity down the street. Might be a good starting point.
Peace,
John Burns
Shop Owner