🔍 Key Concepts

• Navigation Rules, Rule 33 – Equipment for sound signals • Annex III – Technical details of sound signal appliances (bell and gong requirements) • How sound signal requirements change with a vessel’s length (thresholds at 12 m, 20 m, and 100 m)

💭 Think About

• Is the requirement for a gong based more on the type of vessel (power vs. sail) or on the length of the vessel? • Think about when a vessel needs only a bell, and when it must have both a bell and a gong. What length triggers that extra requirement? • Does the rule say this applies to a specific class (like power-driven only), or does it say any vessel once it reaches a certain length?

✅ Before You Answer

• Look up the exact length in meters at which a gong is required in Rule 33 and Annex III. • Confirm whether the rule says “any vessel” or specifies power-driven or sailing vessels. • Verify that you are not confusing the length thresholds for whistles, bells, and gongs—each has its own minimum vessel length.