I don't really know how much of a learning curve there really is compared to diving with a tank. So, where in Chile can I experience to dive with a hose and an air compressor? Preferably within a safe environment / with a diving instructor and not a crazy fisherman.
If you Google for the Spanish term "escuela de buceo comercial chile", on of the top five hits is this school here, which offers such courses. they take 6 weeks. They are located in Talcahuano, Chile.
You need to consider that surface supplied diving is very expensive and complicated. The equipment required for this is a huge factor in this. See wikipedia for more info. Scuba can be learned in 3 days instead for example. You will be learning a new profession, not a hobby.