Final answer:
When encountering an unresponsive, apneic, and pulseless individual due to a massive stroke, the recommended action is to apply an AED and deliver a shock if indicated.
Step-by-step explanation:
According to the information provided, the correct action to take when encountering a 66-year-old male who is unresponsive, apneic, and pulseless due to a massive stroke is to apply an AED and deliver a shock if indicated. CPR is not recommended in this situation because it is ineffective in the water. The priority should be to remove the individual from the water as quickly as possible before initiating CPR.