Types of Sound Signals

Navigation lights must be exhibited from sunrise to sunset. Except when it has been determined that a risk of collision does not exist, every vessel that hears apparently forward of the beam the fog signal of another vessel must reduce her speed to the minimum that she can be kept on course; take all way off if necessary; or navigate with extreme caution until the risk of collision is over. Lookout In restricted visibility, lookouts are placed as far forward and as low to the water as possible. There must be two at each station, one to serve as the lookout and the other as the phone talker. They report everything they see or hear. Give-way Vessels All vessels are give-way vessels in restricted visibility. They are required to maneuver to avoid each other and to avoid turning towards any fog signals heard. Only the required fog signals will be sounded unless vessels sight each other, in which case the Figure 9-29.—Vessel constrained by her draft. normal steering and sailing whistle signals will be sounded. Equipment Each power-driven vessel must have a whistle, a bell mounted in the forward part of the vessel, and for a vessel 100 meters or more in length, a gong in the after part of the vessel. Vessels less than 12 meters are not required to have the whistle, bell, and gong, but they must have the means to make an efficient signal. Types of Sound Signals A prolonged blast is one of from 4 to 6 seconds in duration; a short blast is about 1 second in duration. As can be seen in figure 9-30, fog signals are sounded at 2-minute intervals unless otherwise noted. A power-driven vessel making way through the water in a fog or thick weather of any kind is required by the International and Inland Rules to sound a prolonged blast at intervals of not more than 2 minutes. Under both sets of rules, a power-driven vessel under way but stopped, and having no way on sounds two prolonged blasts, with about 2 seconds between them, at intervals of not more than 2 minutes. 9-30