Nautical facts of cruise life

2013-05-14 10:38
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Battle of the Cunard Queens

Take a look at the Cunard fleet made up of the Queen Victoria, Queen Elizabeth and its flagship transatlantic liner the Queen Mary 2.

“It is not that life ashore is distasteful to me. But life at sea is better.”  - Sir Francis Drake

A truism you’ll discover after your first cruise – and if you’re not careful it is surely a holiday style that can become addictive for its laid back approach and enforced relaxation.

Here’s a novel look at some of the nautical terms and references...


A delayed departure when embarking on a cruise is the last thing anybody hopes for. Sometimes it happens though. Not to be confused with its aeronautical counterpart, it’s the job of the pilot to ensure a smooth entry and exit of ports or narrow coastal passage ways. Usually a qualified coastal navigator and often an ex-captain, the pilot assists the bridge with their local knowledge of tide and currents or wind and weather conditions. Some ports require compulsory use of a pilot, specifically for ships over a certain size but their function is purely advisory and the Master or Captain is still fully responsible for the ship and her safety.

Ship’s stabilisers

Down rolling is often the root cause of many an unsteady passenger and the much dreaded seasickness. But thankfully since the 1930s large passenger ships have been using stabilisers to counter the effect. Operated by gyroscopic control, a steadier and more comfortable passage is achieve when these retractable, pivoted fins or horizontal rudders come into play and are automatically adjusted against the ships tendency to roll.

The Queen Mary 2 is fitted with four 20-megawatt asi-pods. Two are fixed, while the remaining two have full 360-degree rotation. (Selene Brophy)


An abbreviation for radio direction and range, radio wave pulses detect and measure the distance of unseen objects – an instrument that undoubtedly would have ensured a happier ending for ships such as the Titanic. The idea of radio detection is almost as old as the Radio itself but the breakthrough of the technology came in the 1940s with the British invention of the Magnetron to measure very short wavelengths. Used mainly in warships in the beginning for shadowing an enemy, it was later installed on merchant ships to aid navigation and prevent collisions.

Pollywogs and Shellbacks

The ancient tradition of the Crossing the Line Ceremony celebrates a sailor’s first crossing of the equator. If you haven’t crossed the line you’re known as a Pollywog and once you have earned your right of passage from Neptune and his Seaweed court of mermaids, sailors are then awarded the status of Shellback. Seeded in the ancient traditions of the Greeks, the ceremony was seen as a test to see if sailors could handle long, rough trips to sea. The modern equivalent however entails hilarious humiliation of the pollywogs as they’re doused in a horrible mix of sludge and made to kiss a dead fish, providing entertainment for King Neptune’s court and the other Shellbacks on board.

Neptune's court in session - granting safe passage for pollywogs as they earn their title of Shellbacks. (Selene Brophy)

Nautical mile

The measurement unit of a mile is usually 5 280 feet. At sea however the mile has a more mathematical foundation. The nautical mile is the length of one minute (one sixtieth of one degree) of latitude but the earth is not a perfect sphere and is flattened at its Poles. This means that the length of one minute will be 6 046 feet at the Equator and 6 108 feet at the poles. To overcome the discrepancy a standard 6 077 feet is actually used as the measurement of a sea or nautical mile. The international nautical mile is a standard fixed length of 1 852 meters.

Nautical Twilight

This is the period in the morning and the evening when the sun is between 6 & 12 degrees below the horizon. Sailors often took navigational observations during this time of the day as visibility was ideal. While many think of twilight as the time when darkness approaches, this period of the day is actually broken up into several distinct categories – Civil twilight occurs when the sun is less than six degrees below the horizon, next would be nautical twilight followed by astronomical twilight between 12 and 18 degrees and when the sun is less than 18 degrees below the horizon, it is considered night. But the dark sky should have told you that.

Twilight north of the Equator. (Selene Brophy)

Highest waves

The highest wave ever recorded had a height of 34m. The factors influencing the height of the wave include wind speed, how long it has been blowing and the distance the wave has travelled. It is also interesting to note 94% of the Earth’s water is found in its oceans. Salinity of the water varies, depending on if the sea water is enclosed and cannot mix with seawater from larger oceans. An example of this would be the Mediterranean and the Red Seas. Sodium and chlorine (sodium chloride in its solid form or salt) together with magnesium, calcium and potassium make up over 90% of the elements dissolved in sea water.

Great circle

The only time a straight line is not the shortest distance between two points happens to be when they’re on opposite sides of the ocean. While a course plotted on a nautical chart may appear straight, the curvature of the earth’s surface means it’s not. Navigators often chart what is known as a Great Circle for a long ocean voyage. It has the same circumference as the sphere it is being drawn on and, like the equator, divides the sphere or earth into two equal hemispheres – the difference being that the Great Circle can be drawn at any point on the earth’s surface. By following this course instead of a straight line, the navigators are able to cut a considerable distance off the journey. An example of the Great Circle route between Southampton and New York is an estimated 70 nautical miles shorter than the thumb track.


No, we are not referring to the over-used Australian colloquialism. Mate is the recognised term for a watch-keeping officer and is used as such by the International Maritime Organisation. This term developed in the era of merchant ships and means the officer next to the Captain, able to deputize him when necessary. It formed part of the hierarchy of merchant service officers, chief officers, and chief mates all the way down to the junior fourth mates aboard ocean liners.
Read more on:    travel international

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