It is not the case of diving well although no doubt you do, it is the instructing, or teaching to use another term that you no doubt do well... this is the transferable skill.I might leave the game, if i could do anything else well or at least as well as diving, its a real problem at times.
I went to driving, that went well for the best part of a decade before I lost interest and a combination of higher running costs and people starting the pathetic tactic of devaluing the local industry by undercutting each other made it less desirable than it was a few years ago.
I picked up a NVQ assessors ticket along the way, this is transferable to any area I have experience in.
Don't think of yourself as a diving instructor, you are an instructor, these are skills you should not underrate.
Me? Bored of the rat race I have made a nest for myself within the public sector, at a time when they were not taking on staff who were not already on the payroll I took a contract covering a long term sick employee, they returned and a job was created to keep me there on a permanent contract with full public sector perks and there I shall stay til retirement, TBH I already feel semi retired, I have never had it so easy, I have more free time than I know what to do with.
Do not believe your talents and experience are not transferable....