Practice Test Geeks(OBS) Online Boating Safety Certification Practice Test
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Navigation & Route Planning Flashcards

7 cards from real OBS practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Navigation & Route Planning flashcards as text

  1. What does a green square daymark on a fixed structure indicate?

    Answer: Starboard side of a channel when proceeding toward open sea

    Green square daymarks (like green cans and lights) mark the starboard side of the channel when heading away from open water — leave them to starboard outbound.

  2. How is a 'nautical mile' different from a 'statute mile'?

    Answer: A nautical mile is longer, equal to approximately 6,076 feet

    One nautical mile equals approximately 6,076 feet (1,852 meters), making it about 15% longer than a statute mile of 5,280 feet.

  3. What should a boater do first when they realize they are lost or disoriented on the water?

    Answer: Stop the vessel, assess surroundings, and attempt to identify position using visible landmarks or GPS

    Stopping to assess your surroundings and attempting to establish your position prevents the situation from worsening.

  4. What is the significance of a 'preferred channel' buoy (red and green banded)?

    Answer: It marks a channel junction where one channel is preferred over another

    Red and green horizontally banded buoys mark channel junctions or bifurcations, with the top color indicating the preferred (primary) channel.

  5. A boater is anchoring overnight in an unfamiliar bay. What chart feature should they check FIRST?

    Answer: Water depths, bottom type, and any underwater obstructions or cables in the area

    Checking depths, bottom composition (for anchor holding), and hazards like cables ensures a safe and secure anchorage.

  6. What does 'variation' mean on a nautical chart compass rose?

    Answer: The angular difference between true north and magnetic north at that location

    Magnetic variation is the angle between true geographic north and magnetic north, which differs by location and changes slowly over time.

  7. When planning a route near a coastline with rocks and shoals, what minimum clearance rule do experienced mariners follow?

    Answer: Add a safety margin of 10–20% to the charted depth when calculating minimum safe depth

    Adding a 10–20% safety margin to charted minimum depths accounts for chart inaccuracies, wave action, and vessel squat at speed.