RYA Yachtmaster Advanced Navigation 2

Question 1

What is a 'running fix' and when is it used?

Accepted Answer

A position fix obtained by taking a bearing of a single object, advancing the position line along the vessel's track, then taking a second bearing of the same or another object

Answer

A running fix is used when only one object is visible. The first bearing is taken and the position line advanced (transferred) along the track made good. When a second bearing is taken, the intersection of the advanced line and new line gives a fix.

Question 2

A depth sounding taken with an echo sounder shows 18.5 m. The tide height is 2.3 m. What is the charted depth at that position?

Accepted Answer

16.2 m

Answer

Charted depth = sounding − tide height = 18.5 − 2.3 = 16.2 m. Subtracting the tide height removes the tidal contribution and gives the depth referenced to chart datum.

Question 3

When planning a cross-Channel passage from the UK to France, which publication gives standard port tidal predictions for English Channel ports?

Accepted Answer

Admiralty Tide Tables, Volume 1 (NP201)

Answer

Admiralty Tide Tables NP201 (European Waters) provides full tidal predictions for standard ports and differences for secondary ports around the English Channel and Western European coasts.

Question 4

A vessel is approaching a headland with a tidal race. How should the skipper time the passage?

Accepted Answer

Arrive at or near slack water or when the stream is fair, before it builds to maximum rate

Answer

Tidal races can produce dangerous overfalls, breaking seas, and confused water. Passage at slack water or during a fair (favourable) stream before it builds is standard practice. Maximum spring rates in a race can be lethal.

Question 5

What is a 'Secondary port difference' in tide tables and how is it applied?

Accepted Answer

A time and height correction listed in tables that, when applied to a standard port's prediction, gives the secondary port's tide

Answer

Secondary port differences include time differences (HW and LW) and height differences (HW and LW heights). These are applied to the standard port predictions after interpolating for the appropriate date.

RYA Yachtmaster Practice Test

RYA Yachtmaster Practice Test

RYA Yachtmaster Advanced Navigation 2