Question 236 Rules of the Road

The correct answer is D) both vessels sound one prolonged blast. According to the International Regulations for Preventing Collisions at Sea (COLREGS) and the Inland Navigation Rules, a "head-on" situation at night is deemed to exist when both vessels can see each other's sidelights and masthead lights, and both vessels sound one prolonged blast. The other options are incorrect because: A) the distance between the vessels is not relevant in determining a head-on situation, and B-C) the visibility of the sidelights and masthead lights alone does not define a head-on situation, the sound signal is the key factor.