The discussion revolves around solving for the boat's entry time using the tide equation, where the user initially calculates t = 1 but finds the answer key states t = 2. The mistake is identified in the interpretation of the cosine function, specifically in the transition from the equation to the inverse cosine step. Participants suggest that the textbook may contain an error regarding the tidal cycle, indicating that the time between successive low tides should be 12 hours instead of 6. This leads to the conclusion that the textbook answer might be incorrect, as there are typically two tides per day. The conversation emphasizes the importance of verifying the source material in mathematical problems.