To comply with the rules when meeting another vessel head-on, what should you exchange?

When two vessels are approaching each other head-on, the appropriate sound signal to communicate intentions is crucial to avoid collisions. By signaling with one short blast, a vessel indicates that it intends to alter its course to starboard. This action is in accordance with the International Regulations for Preventing Collisions at Sea (COLREGS), specifically Rule 14, which states that when two power-driven vessels are meeting, each shall alter their course to starboard to pass on the port side of the other.

This practice helps ensure clarity and minimizes the risk of misunderstanding between the vessels. When both vessels agree to exchange a one short blast, they are effectively communicating their intentions and following commonly accepted navigational protocols to maintain safety on the water.