Navigation & Route Planning Flashcards

What does a flashing yellow light on a buoy typically indicate?

Answer: A danger or hazard area requiring caution

Flashing yellow lights mark caution areas, such as traffic separation zones or areas requiring special attention.

A nautical chart shows a depth of 15 feet at Mean Lower Low Water (MLLW). What does this mean for your planning?

Answer: The depth will never be less than 15 feet

MLLW is the charted datum (reference level), so actual depths are at or above the charted figure under normal conditions.

When using a paper chart, what tool is used to measure distances?

Answer: Dividers or a compass

Dividers are used to measure distances on a chart by comparing the spread against the latitude scale on the chart's border.

What is a 'range' in coastal navigation?

Answer: Two objects aligned to indicate a safe navigational track

A range consists of two fixed markers that, when aligned, guide a vessel safely along a specific track or into a channel.

What is 'dead reckoning' navigation?

Answer: Estimating current position using last known position, speed, heading, and time

Dead reckoning calculates an estimated present position from a known past position, accounting for speed, direction, and elapsed time.

You are operating in fog and hear one prolonged blast every two minutes from another vessel. What type of vessel is signaling?

Answer: A power-driven vessel making way through the water

A power-driven vessel making way through the water in restricted visibility sounds one prolonged blast at intervals of not more than two minutes.

On a nautical chart, magenta (pink/purple) coloring is used to indicate:

Answer: Aids to navigation, restricted areas, and important caution notes

Magenta on nautical charts highlights lights, restricted areas, traffic separation schemes, and other important navigational information.