Code of Federal Regulations Title 46. Shipping § 46.140.630 Lookout

(a) Throughout the trip or voyage the master and officer in charge of the navigational watch must assess the requirement for a lookout, consistent with 33 CFR 83.05. A lookout in addition to the master or mate (pilot) should be added when necessary to:

(b) In determining the requirement for a lookout, the officer in charge of the navigational watch must take full account of relevant factors including, but not limited to:  state of weather, visibility, traffic density, proximity of dangers to navigation, and the attention necessary when navigating in areas of increased vessel traffic.