OP
Rule #19 is the first and only Rule in Section III of Part B. It applies anytime vessels are not insight of one another because of restricted visibility. Many believe that this rule applies anytime visibility is restricted, however, this is not the case. If, when operating in restricted visibility, the other vessel can be seen visually, this Rule does not apply. If another vessel is detected by radar or hearing alone, Rule #19 must be followed. However, the moment that the other vessel breaks out of the fog bank and is sighted the other Steering and Sailing Rules come into effect.
This Rule applies to vessels "navigating in or near an area of restricted visibility." This means that if you are in an area of good visibility but can see a fog bank, rainstorm, or other area of restricted visibility, you are required to follow the provisions of this Rule. Remember, there may be a vessel in a fog bank not aware of your presence.
The Rule also addresses the subject of safe speed, which is to be "adapted to the prevailing circumstances and conditions of restricted visibility." This speed requirement is coupled with the requirement that a "power-driven vessel" shall have her engines ready for immediate maneuver." This requirement should be considered to apply to any vessel fitted with an engine, including fishing vessels, vessels restricted in ability to maneuver, and vessels not under command. Remember, Rule #18 does not apply in restricted visibility, so hampered vessels get no special privileges.
Any action taken to avoid collision in restricted visibility should, when possible, be taken earlier and result in a greater passing distance than would be necessary when in sight. Any course change taken should be large enough to be readily apparent on radar as described in Rule #8.
This Rule applies to vessels "navigating in or near an area of restricted visibility." This means that if you are in an area of good visibility but can see a fog bank, rainstorm, or other area of restricted visibility, you are required to follow the provisions of this Rule. Remember, there may be a vessel in a fog bank not aware of your presence.
The Rule also addresses the subject of safe speed, which is to be "adapted to the prevailing circumstances and conditions of restricted visibility." This speed requirement is coupled with the requirement that a "power-driven vessel" shall have her engines ready for immediate maneuver." This requirement should be considered to apply to any vessel fitted with an engine, including fishing vessels, vessels restricted in ability to maneuver, and vessels not under command. Remember, Rule #18 does not apply in restricted visibility, so hampered vessels get no special privileges.
Any action taken to avoid collision in restricted visibility should, when possible, be taken earlier and result in a greater passing distance than would be necessary when in sight. Any course change taken should be large enough to be readily apparent on radar as described in Rule #8.