Two boats are operating near each other. One of these boats must take early and substantial action to keep well away from the other boat. Which is the boat that must take action?

In navigational terms, the give-way vessel is the one that must take early and substantial action to avoid collision when two boats are operating near each other. This vessel is required to yield the right of way to the other vessel to ensure safety on the water.

The stand-on vessel, on the other hand, has the right of way and can maintain its course and speed. However, it must still be vigilant and prepared to take evasive action if it becomes apparent that the give-way vessel is not taking necessary steps to avoid a collision.

The concepts of port and starboard sides refer to the relative positioning of vessels, but they do not inherently determine which vessel must give way. Instead, these terms are helpful in understanding navigation rules and right of way under specific circumstances.

Thus, the give-way vessel represents the boat that must prioritize the safety of navigation by taking action to avoid any potential accidents.