Hi, Derek:
Now, amongst the agencies, there are some different training philosophies. Some tend to turn out divers (in their basic open water course) who for the most part are capable of handling good conditions; warm tropical Caribbean waters with good-to-excellent visibility, either shore diving or a charter boat with the group led around (& back to the boat) by a dive master, with minimal current and no big issues with tide, either. Local gravel quarries re-purposed as scuba sites are also good options. Such divers may go on to take additional formal coursework or train under seasoned mentors informally to build their skills for more challenging environments. This breaks training into sequential pieces, the 'bite-sized' approach, and is popular with many divers. This is what I did, basically.