The above is a diagram of certifications I have obtained throughout my 17 year diving career. What I neglected to add were the words, "To be continued." Why? Because I do not look at my diagram and see what I have accomplished; instead, I see what certifications I would like to add. At no point would I ever say a diver is done learning...there are always new skills, new techniques and new experiences which can encourage a diver to continue learning and enhance their existing abilities. A diver’s open water certification is merely the gateway to a lifetime of learning, not a final destination in itself.
Continuing education in diving can lead divers down many paths. The first step is to determine what your end goal is. Some divers purely want to enjoy the sport as a non-professional recreational diver. Though bettering themselves through specialties and new experiences, they are not interested in pushing the boundaries of depth or time and they do not want to be burdened with the liability of looking after other divers in the water. Some, however, like the idea of being able to share (and educate) others in their passion. They continue on to become professional divers and, in some capacity, are involved in teaching people how to scuba dive or end up working in the industry sharing the underwater world with their fellow divers. Still others like the idea of pushing those non-decompression limits (NDL), whether they go deeper than the recreational dive planner (RDP) or stay longer (and thus load more nitrogen) than is taught in recreational diving. These divers are not necessarily going deep and staying longer just for the sake of doing it...oftentimes they are exploring caverns or wrecks, which takes time. And some divers become commercial divers, finding a way to make considerable money working in the water either fishing, welding, or conducting inspections on underwater infrastructure.
Once you determine your end goal, evaluate the different certifications needed to get you there. Some certifications that exist to improve your skills are tied to experience (i.e., Advanced Open Water, Rescue Diver), while others broaden your experiential horizon (think specialties). You should also evaluate the different certifying agencies that exist to get you where you want to go. Different agencies will emphasize different skills or certifications; some may be more geared toward scientific diving (i.e., NAUI), while others focus on technical diving (i.e., TDI, IANTD) or public safety diving (i.e., ERDI). Nuances within certification programs make it possible for divers to find a certifying agency that best suits their needs and can help them achieve their goals.
After you have completed your research, make your plan. How are you going to achieve your goals? Perhaps you set deadlines for when you want to have certain certifications completed. Or maybe you just need to bite the bullet and sign up for that class your local dive shop is offering. Find a dive buddy with similar goals and you can work together to achieve them.
Finally, dive your plan. Get out there and achieve your dreams! And do not forget to regularly reevaluate your goals...course corrections help you to fully realize your dreams by allowing you to further focus on what it is you really want to achieve.