1.3 The Lookout & Safe Speed (Rules 5-6)

Rule 5 — Look-out

Rule 5 is short, absolute, and heavily tested. Learn it close to verbatim:

"Every vessel shall at all times maintain a proper look-out by sight and hearing as well as by all available means appropriate in the prevailing circumstances and conditions so as to make a full appraisal of the situation and of the risk of collision."

Three phrases carry the weight:

• "At all times" — there is no condition, day or night, calm or crowded, in which a lookout may be dropped.
• "By sight and hearing as well as by all available means" — a lookout is not only your eyes. It includes your ears (a fog signal, breaking surf, another engine) and all available means, which on a modern vessel includes radar, AIS, and VHF radio. Failing to use a radar you have aboard is a Rule 5 violation.
• "Full appraisal of the situation and of the risk of collision" — the purpose of the lookout is to detect and evaluate risk early, before a close-quarters situation develops.

Can the operator be the lookout? On a small uninspected passenger vessel in open water with good visibility, the person steering may also serve as the lookout. But Rule 5 combined with Rule 2 (good seamanship) means that in heavy traffic, restricted visibility, or when your attention is divided (navigating a tricky channel, tending passengers), a proper lookout may require a dedicated, second set of eyes and ears whose only job is watching. On the exam, when a scenario adds fog, darkness, or traffic to a single-handed helmsman, the safe answer trends toward post a dedicated lookout.

Rule 6 — Safe Speed

Rule 6 requires that:

"Every vessel shall at all times proceed at a safe speed so that she can take proper and effective action to avoid collision and be stopped within a distance appropriate to the prevailing circumstances and conditions."

The key idea is that "safe speed" is not a number — it is whatever speed lets you stop or maneuver in time. In thick fog inside a crowded harbor, a safe speed might be 3 knots; on a clear open bay it might be cruising speed. The rule then lists the factors you must weigh, and the exam loves to ask you to identify them.

Factors to be considered by ALL vessels:

1. The state of visibility.
2. The traffic density, including concentrations of fishing vessels or any other vessels.
3. The maneuverability of the vessel, with special reference to stopping distance and turning ability in the prevailing conditions.
4. At night, the presence of background light such as from shore lights or from the back-scatter of the vessel's own lights.
5. The state of wind, sea, and current, and the proximity of navigational hazards.
6. The draught in relation to the available depth of water.

Additional factors for vessels with operational RADAR:

1. The characteristics, efficiency, and limitations of the radar equipment.
2. Any constraints imposed by the radar range scale in use.
3. The effect of sea state, weather, and other interference on radar detection.
4. The possibility that small vessels, ice, and other floating objects may not be detected by radar at an adequate range.
5. The number, location, and movement of vessels detected by radar.
6. The more exact assessment of visibility that may be possible when radar is used to measure the range of nearby vessels.

Safe speed is never a fixed number. There is no posted speed limit in the rules; the same 20 knots can be perfectly safe on an empty offshore leg and grossly unsafe in a fog-bound anchorage. When a question offers a specific knot value as "the safe speed," it is almost always the wrong answer — the rule-correct choice describes a speed at which the vessel can stop or maneuver in time for the conditions. Rule 6 also interacts with Rule 19: in restricted visibility a power-driven vessel must keep her engines ready for immediate maneuver and, when a close-quarters situation is developing ahead, reduce to the minimum at which she can be kept on course — bare steerageway — which is nothing more than safe speed applied to fog.

Worked Reasoning: Fog on a Busy Bay

Suppose you operate a six-pack charter and fog rolls in until visibility drops to about 200 yards on a bay dotted with anchored fishing boats. Applying Rules 5 and 6 together: you must post a dedicated lookout (Rule 5, because your own attention is on the helm and instruments), slow to a speed at which you could stop in well under 200 yards (Rule 6 — visibility, traffic density, stopping distance), use your radar if fitted (part of "all available means" and a Rule 6 radar factor), and remember that small anchored skiffs may not paint on radar (a specific radar factor). Notice how the two rules interlock — a strong safe-speed answer almost always includes a lookout and instrument component.

Exam Framing

Rule 6 questions usually take one of two forms: "Which of the following is a factor in determining safe speed?" (the answer is any item from the lists above), or a scenario asking what speed is safe (the answer is a speed at which you can stop or maneuver within the prevailing conditions, never a fixed knot value). Keep the two lists — all-vessels versus radar-equipped — mentally separate, because the exam sometimes asks which factors apply specifically to vessels using radar.