While rendering passing honors to another vessel, if you hear three blasts of the whistle, what action should you take?

When hearing three blasts of the whistle while rendering passing honors to another vessel, you should carry on with your duties. The three blasts indicate that the vessel you are passing is acknowledging your honors and continuing its own operations. The appropriate response in this situation is to maintain your course and speed, signaling that you are aware of the exchange and will proceed without altering your actions. This reinforces the professionalism and decorum expected in naval operations while demonstrating respect for the customs of the sea.

Choosing to carry on signifies compliance with naval traditions during passing honors, allowing for a smooth and respectful interaction between vessels. Other responses, such as standing at attention or saluting, are not necessary in this specific context, as the three blasts indicate that the formal acknowledgment has been made. Preparing for boarding is also not relevant, as this action would imply a quite different operational scenario that does not pertain to passing honors.