Your instructor may recommend or even require that you take an additional pool training session before moving forward(additional fees will apply). Many of us don’t take this kind of news well and the decision may interfere with vacation plans. It may also save your life. Your instructor has experience teaching basic pool sessions and knows what the ocean sessions will demand of you. Listen to your instructor when they quietly pull you aside and recommend a recycle.
Your instructor must adhere to a set of standards set by the Professional Association of Diving Instructors(PADI) and the RSTC. They have years of experience and training assessing would be graduates. Trust your instructor’s decision.