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Powerboat ICC revision module 8 of 9

RULE

COLREGs and Buoyage for Powerboats

Lookout and safe speed, collision risk, encounter duties, narrow channels, local controls, and Region A buoyage evidence.

8 guided lessons · 8 practice questions · 8 flashcards

Lesson previewLookout and Safe Speed Form One Control1 section shown

Preview lesson

Lookout and Safe Speed Form One Control

What you will learn

Connect a proper lookout to a condition-specific safe speed, then identify when an incomplete picture requires more time, view, crew attention or stopping room.

Lookout and speed are not separate checklist items. A powerboat must be slow enough for the lookout that is actually possible, and the lookout must be complete enough to support timely action.

Rule 5 requires a proper lookout by sight, hearing and every available means appropriate to the circumstances. That includes listening, scanning blind sectors, using a briefed crew member and interpreting available navigation equipment without letting any display replace the outside picture. The duty continues in clear weather, familiar water and low apparent traffic.

Rule 6 defines safe speed by outcome: the vessel must be able to take proper and effective action to avoid collision and stop within a distance appropriate to the prevailing circumstances. Visibility, traffic density, manoeuvrability, background lights, wind, sea, current and nearby hazards all matter. A limit or usual planing speed is only one input; it does not certify the live speed as safe.

Powerboat attitude and workload can shrink the effective picture. MAIB cases show why blind arcs, speed and divided attention deserve explicit control, but those cases do not provide a universal safe speed. Restore view and thinking time before the unseen sector or uncertain target becomes a close-quarters problem.

Powerboat COLREGs and buoyage decision board

Classify the whole picture before choosing the action

Compare six constructed cases through one trace: observe the scene, identify the governing rule or mark, state the duty, choose a bounded control, confirm its effect and keep a clear boundary that stops or changes the plan.

Blind arc in a busy estuary

The weather is clear, but the powerboat's bow-up attitude hides water ahead while moored craft, tenders and paddle users occupy the estuary. A passenger points forward before the helm sees the concern.

  1. 1Observed picture
  2. 2Rule or mark classification
  3. 3Required duty
  4. 4Bounded control
  5. 5Confirmation
  6. 6Stop / change boundary
Observed picture
The visible scene is incomplete and the passenger cue is unconfirmed. Clear weather does not remove the blind sector or shorten stopping distance.
Rule or mark classification
Rules 5, 6 and 7 remain connected: maintain a proper lookout, use a safe speed and assess risk with every appropriate available means.
Required duty
Restore time, view and shared attention before the hidden sector becomes a close-quarters problem.
Bounded control
Reduce exposure, stabilise the observation, assign an explicit crew lookout and rebuild the ahead picture before speed is reconsidered.
Confirmation
The previously hidden water, traffic trend, stopping room and crew report agree; continued scanning remains owned rather than assumed.
Stop / change boundary
Do not treat familiar water, a clear day, a passenger warning or a momentary glimpse as proof that the lookout and safe-speed duties are satisfied.
Constructed revision cases only. This board cannot see, hear, identify or track a real vessel or aid; establish visibility, risk of collision, safe speed, safe distance, water depth, clearance, conventional direction, local rule or legal duty; prescribe a course, speed, passing side or manoeuvre; assess competence; or replace the complete current COLREGs, charts, notices, local directions, official publications and recognised practical instruction. Every state has a text heading and full description; no meaning depends on colour.

Worked example

A powerboat is travelling through a clear but busy estuary. Bow-up attitude hides water ahead and a passenger reports a small craft in the blind sector.

  1. 1Treat the passenger report as an unresolved lookout cue rather than proof of target type or clearance.
  2. 2Restore time and view by reducing exposure through the trained boat-specific method.
  3. 3Assign a clear lookout sector and confirm the report against the outside picture and available equipment.
  4. 4Reconsider speed only after the hidden sector, traffic trend and stopping room form one coherent picture.

Sense check: Clear visibility outside the blind arc cannot make unseen water safe, and a written case cannot choose the real boat's speed.

Lookout and Safe Speed Form One Control
Blind sector or sprayHow will the view be restored and continuously owned?A passenger looked once
Dense or mixed trafficIs there time to detect, classify, act and confirm?The legal limit permits this speed
Background lights or poor visibilityWhich means can corroborate the weak visual picture?The display sees everything

Repair the incomplete picture

The helm says that familiar water and clear weather make the present planing speed acceptable.

  1. 1. Observe

    Name blind sectors, traffic, hazards, visibility and current stopping room.

  2. 2. Slow the decision

    Preserve enough time for detection, classification and an effective response.

  3. 3. Own the lookout

    Brief sectors and reports without handing away the helm's responsibility.

  4. 4. Recheck

    Confirm that the picture and response room remain adequate as conditions change.

Sense check: Familiarity and a speed limit do not answer the Rule 5 and Rule 6 questions for the present conditions.

Common mistake or limitation

  • Equating safe speed with the posted maximum or a familiar planing speed.
  • Treating a crew warning, plotter target or one visual scan as a complete lookout.
  • Waiting for positive target identification before preserving time and stopping room.

Recap

  • Proper lookout uses sight, hearing and every appropriate available means.
  • Safe speed is an outcome in live conditions, not a fixed number.
  • Blind sectors and workload change the usable picture even in clear weather.
  • Restore time and view before uncertainty becomes close quarters.

Optional quick check

Section 1 of 1

Which finding most clearly means lookout and safe speed must be reconsidered together?

Choose one answer