Which of the following is a rule of operator responsibility?

The principle of operator responsibility emphasizes the importance of situational awareness and attentiveness while operating a watercraft, which is why staying alert is the correct choice. An operator who is attentive to their surroundings can better respond to changing conditions, obstacles, and the actions of other vessels. This vigilance is crucial for ensuring the safety of everyone on board and those in nearby watercraft.

Being alert allows the operator to be proactive in avoiding potential hazards and making informed decisions, thus enhancing the overall safety of the boating experience. Other options, while they may have some relevance in specific situations, do not encompass the broad responsibility that comes with operating a vessel. For instance, following other boats can be risky if not done at a safe distance; remaining seated may not always be practical depending on the type of vessel and conditions; and limiting speed, while important, does not address the essential need for constant awareness on the water.