Question of the Week2018-10-04T19:10:04-07:00

Question of the Week

In an industry where it is possible to dance on ceilings and lean against floors, there are bound to be questions. Every week we will post some here — along with our best answers.

Rule 9: Narrow Channels

One of the thornier Rules of the Road, Rule 9, Narrow Channels, addresses navigation in particularly precarious areas. Because narrow channels proliferate on waters shoreward of demarcation lines, it is not surprising that there are a number of significant differences between the International (COLREGS) and the Inland versions of [...]

The SS American Mariner

In the 1950s, the US Maritime Administration commissioned several classes of single-screw break bulk cargo vessels. The SS American Mariner, technically a C4-S-1a vessel, is used in US Coast Guard examinations as the platform for various stability calculations. Originally these questions only appeared on Unlimited Master AGT and Unlimited [...]

Loading & Unloading Oil Cargoes: Calculations

Many of the Deck Examinations on the new "Q" tests contain two types of questions about loading and unloading oil cargoes. Both require calculation. The first asks for a quantity. The second wants to know the time and date of final loading. To determine the quantity of oil cargo [...]

Elbow Room: Staying Within an Anchorage

You are arriving in port and are assigned to anchor in anchorage circle B-4. It has a diameter of 500 yards and your vessel's LOA is 484 feet. If you anchor in 8 fathoms at the center of the circle, what is the maximum number of shots of chain [...]

Minimum Freeboard

At small angles of inclination, a vessel’s stability is indicated by her metacentric height (GM). But when a vessel encounters conditions that cause her to roll, heave, pitch, sway and yaw excessively, for example in heavy or rough seas, it is her reserve buoyancy that counters the effects of [...]

Anchor Whelps

It is hard to imagine the pleasure of drinking wine being diminished by not knowing the name of the indentation in the bottom of the wine bottle.  And plenty of shoes have been successfully tied by people who do not know the name of the thingamajig at the end [...]

ETA (Estimated Time of Arrival)

Near Coastal and Celestial examinations for deck licenses will often include an ETA (Estimated Time of Arrival) problem. The more interesting of this type are trans-Pacific crossing the International Date Line. The trick to these problems is not to think — not to think about the Date Line or the [...]

Get Smart, Go Astern

In a study published in Psychological Science (May 2009), Dutch researchers determined that “Backward locomotion appears to be a very powerful trigger to mobilize cognitive resources.” The Rules of the Road anticipated this conclusion in Rule 8 by advising that “if a vessel needs more time to avoid collision [...]

Chart Projections

In 1849, Dr. Samuel Birley Rowbotham published the pamphlet “Zetetic Astronomy: Earth Not a Globe”  in which he asserted that the Earth is an enclosed plane, surrounded by the ice of Antarctica and (somehow) suspended over which are the stars, the Sun, the Moon and the planets. Nearly three hundred [...]

“Full and Down” Calculations

“Full and Down” describes the desirable but rare condition in which a vessel has all her cargo space filled and is loaded down to her Plimsoll marks.  Achieving the state of “full and down”  requires some arithmetic.  The old examination bank of questions has three “full and down” problems, two of which [...]

Calculating Board Feet

Occasionally it is necessary to calculate the number of board feet in a pile of lumber.  The key to the problem is knowing that a board foot is 1′ (long) x 1′ (wide) x 1″ (high).  In other words in every cubic foot of lumber (1′ x 1′ x 1′), [...]

Marine Insurance & the Restraint of Rulers, Princes or People

Masters and Chief Mates are occasionally asked the following question: What is an example of the term "Restraint of Rulers, Princes, or Peoples" in a marine insurance policy? A. A prohibition from loading a cargo from a country's government interference B. Arrest of a vessel by legal authorities to [...]

Submarine Emergency Identification Signals

The US Navy has long authorized certain submarine emergency identification signals.  In the past, these signals could be found in Chapter 1 of a current Coast Pilot.  No more.  Notice to Mariners No. 1, the first publication each year of the weekly NTMs, includes a section called “Special Notice to Mariners [...]

The Great Lakes

In the past, with the exception of examinations specific to Great Lakes’ licenses, USCG “Rules of the Road” questions have not asked for the extended definition of these waters as described in Rule 3(m) Inland. They do now. The mnemonic “HOMES—H(uron), O(ntario), M(ichigan), E(rie), S(uperior)” no longer suffices to answer [...]

Reeving a Block

Archimedes boasted “Give me a lever long enough and a fulcrum on which to place it, and I shall move the world.” An application of the same mighty principle of leverage is found in the blocks and tackles that are used to lift weights on board ship and in the [...]

Magnificent Beast: The Northern Right Whale

In order to protect the dwindling number of Northern Right Whales, the “Marine Mammal Protection Act” of 1972 mandated that the amazing “Eubalaena Glacialis” be given wide berth by, among others, mariners.  As reported in The New York Times in March 2009, the MMPA was working; the population of Northern [...]

Chronometer Error and Chronometer Rate

Greenwich Mean Time is invaluable to the navigator and the chronometer is the instrument which provides it. But like any instrument, the chronometer is subject to error. Routinely, candidates for Ocean and Near Coastal deck credentials are required to determine Chronometer Error and Chronometer Rate. This week we will [...]

How to Determine the Size of a Shackle

Shackles are a primary means of connecting the parts of rigging systems on vessels and industrial cranes.  In its simplest form, a shackle is a U-shaped piece of metal secured by a clevis pin, screw or bolt at its opening.  Shackles range in size from one extraordinarily large forged [...]

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