DWO Navigation and Safety 2 — Questions and Answers
Question 1: Under COLREGS Rule 16, what action must a give-way vessel take?
- Maintain course and speed
- Take early and substantial action to keep well clear (Correct answer)
- Sound one short blast and turn right
- Stop engines immediately
Correct answer: Take early and substantial action to keep well clear
Rule 16 requires the give-way vessel to take early and substantial action to keep well clear of the stand-on vessel.
Question 2: What is the maximum permitted cross-track error (XTE) when navigating a vessel in restricted waters under most company SMS policies?
- 0.5 nautical miles
- 0.1 nautical miles (Correct answer)
- 1.0 nautical miles
- 2.0 nautical miles
Correct answer: 0.1 nautical miles
Most SMS policies and port authority requirements limit XTE to 0.1 nautical miles in restricted or confined waters.
Question 3: A vessel is overtaking another in a narrow channel. Which COLREGS rule primarily governs this situation?
- Rule 13 (Correct answer)
- Rule 15
- Rule 18
- Rule 10
Correct answer: Rule 13
Rule 13 governs overtaking situations, requiring the overtaking vessel to keep out of the way of the vessel being overtaken.
Question 4: When using a parallel index technique, the navigator maintains a fixed distance between the vessel's track and a prominent radar target to:
- Determine the vessel's speed over ground
- Monitor that the vessel stays on track without altering the radar range (Correct answer)
- Calculate the tidal set and drift
- Identify the type of radar target ahead
Correct answer: Monitor that the vessel stays on track without altering the radar range
Parallel indexing keeps a fixed bearing line parallel to the intended track, providing continuous off-track deviation monitoring.
Question 5: According to US regulations, what minimum visibility requires a vessel of 100 meters or more to sound a prolonged blast not more than every 2 minutes?
- Visibility less than 1 nautical mile
- In or near an area of restricted visibility (Correct answer)
- Only in zero visibility conditions
- When another vessel is within 1 mile
Correct answer: In or near an area of restricted visibility
COLREGS Rule 35 requires a power-driven vessel making way in or near restricted visibility to sound one prolonged blast at intervals of not more than 2 minutes.
Question 6: What does a 'safe speed' determination under COLREGS Rule 6 require the OOW to consider?
- Only the charted depth and vessel draft
- Visibility, traffic density, maneuverability, background lighting, wind, sea state, and radar limitations (Correct answer)
- The vessel's gross tonnage and LOA only
- The master's standing orders exclusively
Correct answer: Visibility, traffic density, maneuverability, background lighting, wind, sea state, and radar limitations
Rule 6 lists multiple factors including visibility, traffic, vessel maneuverability, sea state, and radar performance when determining safe speed.
Question 7: A vessel's GMDSS equipment includes an EPIRB. When manually activated, the EPIRB transmits a distress signal on which frequency?
- 156.8 MHz (VHF Ch 16)
- 406 MHz (via satellite) and 121.5 MHz (homing) (Correct answer)
- 500 kHz (MF)
- 2182 kHz (MF)
Correct answer: 406 MHz (via satellite) and 121.5 MHz (homing)
Modern 406 MHz EPIRBs transmit the encoded distress signal to Cospas-Sarsat satellites and also emit a 121.5 MHz homing signal for SAR aircraft.
DWO Navigation and Safety 2
Under COLREGS Rule 16, what action must a give-way vessel take?