i am a driller by profession. i understand the business. you are right sir that water drilling can be a part of the family business. and the knowledge of how to drill can be passed on to children. the most important part of water drilling is how to locate sufficient and strong water 100% of the time. when the client is not assured he can get strong water from the driller, he will be so disappointed that he will not pay you the balance of the contract. thus, after experimenting georesistivity and find it having a low success rate, i looked for other ways, and now the technology of finding sufficient and strong water is now perfect.
the problem with water drilling here in the philippines is, most small time drillers offer 100% success also , then leave or abandon the project. their non-chalant and indifferent attitude towards the client give us a bad name. and also, the business of water drilling is so stiff here that you cannot make water drilling business a steady source of family's income.