Lesson 2: Lookout, Safe Speed and Collision Risk
Lesson 2: Lookout, Safe Speed and Collision Risk
Rules 5–7
Detect risk early enough to make a calm, obvious and effective decision.
Lookout is an active system
A proper lookout combines sight, hearing and every available means appropriate to the conditions. Radar and AIS can support the picture, but neither replaces looking, listening and checking assumptions.
Safe speed is the speed at which you can take proper and effective avoiding action and stop within an appropriate distance. Visibility, traffic density, manoeuvrability, background lighting, wind, sea, current, draught and equipment limitations all matter.
Assessing collision risk
Use systematic observations rather than a single glance. A steady compass bearing with decreasing range is a classic warning, but appreciable bearing change does not guarantee safety at close range or with a very large vessel. If in doubt, risk of collision is deemed to exist.
Scenario check
Scenario: A target remains on nearly the same bearing and its range is decreasing. What is your next assumption?
Show the recommended decision
Assume risk of collision and determine the applicable rule. Do not wait for visual drama before acting.
Rule link: Rule 7.
Source: USCG Navigation Rules.
Educational material only. It does not replace the current official rules, notices, local regulations, proper training or prudent seamanship.