Question 1010 Rules of the Road

The correct answer is C) 4 short blasts. According to the International Regulations for Preventing Collisions at Sea (COLREGS) and the Inland Navigation Rules, a vessel engaged in pilotage duty must sound 4 short blasts on the whistle or horn to indicate its identity signal in fog or restricted visibility. This helps alert other vessels in the area that the pilotage vessel is present and engaged in its duties. The other answer choices are incorrect because they do not match the required 4 short blast signal specified in the regulations for vessels on pilotage duty.