What action must the stand-on vessel take when a risk of collision exists?

In situations where a risk of collision exists, the stand-on vessel is required to maintain its course and speed, which allows it to retain its right of way. This is essential under the COLREGs, as it helps clarify intentions to other vessels, reducing confusion during potentially hazardous encounters.

By staying on its course and speed, the stand-on vessel signals to the give-way vessel that it should take action to avoid a collision. This principle upholds the guidelines established by the COLREGs, which emphasize that the stand-on vessel should not unnecessarily alter course or speed unless it becomes clear that the give-way vessel is not taking the necessary actions to avoid a collision.

If the stand-on vessel were to change course or speed without clear necessity, it could create uncertainty and increase the risk of collision rather than mitigate it. Thus, maintaining course and speed is a vital aspect of navigational safety, reinforcing the rules that govern interactions between vessels at sea.