What does Rule 15 specify regarding crossing situations?

Answer: B — It identifies which vessel must give way when vessels are crossing paths

Rule 15 of the USCG Rules of the Road specifically addresses crossing situations between two vessels. In such scenarios, Rule 15 identifies the "stand-on" vessel and the "give-way" vessel, establishing which vessel is required to hold its course and speed and which one must take action to avoid a collision. The rule helps to clarify responsibilities for mariners when two vessels are on a collision course, ensuring there is a clear understanding of how to handle these encounters and promoting safe navigation. This is particularly important in maintaining both situational awareness and safety on the water since knowing which vessel has the obligation to yield can prevent accidents. The other options do not accurately reflect the purpose of Rule 15; there is no requirement for vessels to stop before crossing, it is not restricted to commercial vessels, and there is no stipulation about a specific speed limit like half-speed in this context.