Both inner earseyes observe where our body is in relation to its surroundings as well as the direction of motion.

All these sensory data will subsequently be processed in the central nervous system, which enables us to balance, move and position ourselves properly in our three dimensional surroundings.
The symptoms of motion sickness appear when the brain receives conflicting messages from the 4 systemslethargy and a slight drowsiness. But for the victims it will usually start with a nauseous feeling and/or a slight cold sweat. Then these symptoms increase, and the face becomes paler, perhaps even greenish. Any attempt to concentrate on a task will worsen this predicament. The nauseous feeling eventually becomes incontrollable, and leads to - sometimes violent - vomiting.

Prevention of seasickness

Hours before casting off you could well use an over-the-counter antihistamine such as meclizine or dimenhydrinate and you should - before and during the voyage - avoid spicy or rich foods, alcohol and apples. For longer trips, a prescription medication called Transderm-Scopolamine patch can be worn behind the ear for up to three days at a time. Side-effects of these medications usually consist of sedation and dry mouth. Interestingly enough : Recent studies have shown that ginger root may be as effective as the other drug treatments but is associated with fewer side effects. If, despite all these precautions, you still notice the early symptoms with one of you crew, act immediately and :

• get the victim out on deck but not in direct sunlight other than steering.
  Steering - as well as studying the horizon works and will help to anticipate the boat’s motion. Else let the victim lay in the cockpit to leeward with closed eyes.
• Steady the yacht, either by heaving to or letting the best helmsman drive the yacht.

Page courtesy of www.sailingissues.com

Customs & port police

• When entering Greece all yachts must clear with port authority, customs and health as well as immigration and currency control.
  The ship’s papers - including a passenger and crew list - will be inspected by the port authority, then customs will issue a transit log, renewable after six months but valid for one year. which allows the yacht to sailing in Greece. The transit log should be issued only to non-EU vessels, or to EU vessels wishing to purchase fuel at duty-free prices. At subsequent ports this transit log may be inspected by the port authority. When leaving Greece, the transit log is returned to customs.
• Yachts must carry their original registration document and ship’s radio licence and one member of the crew requires a certificate to operate the radio/VHF. For EU boats, proof of VAT status is also required. The original insurance certificate and a Greek translation showing third party insurance with the amounts in figures. The minimum amounts are 293470 EURO liability for death or injury by sinking, collision or other cause for crew and third parties, 146753 EURO for damage, 88041 EURO for pollution. The skipper must have an International Certificate of Competence.
• The nights should be spent on board - and not in hotels inland for instance - if not, the harbour master and immigration should be notified. Individual passports are not stamped on entry into Greece by yacht, nor is this required for departure with the same yacht. However, if leaving by another means (by air), the stamps are required by immigration at the point of exit.
• Fishing is only allowed with a snorkel at certain areas. Fishing with scuba gear is prohibited.
• Also to protect archaeological sites, scuba diving is restricted. Permission should be sought locally.
• You as the registered yacht owner should be on board. Yet, if a relative or friend fills in your place, make sure to ask the port police for the proper documentation.
• Chartering by foreign yachts is allowed since 2002, but your yacht should be inspected and certificated according to Greek law, a proces that involves a huge amount of red tape.
• Hauling out a yacht requires authorisation of the port police.
• When entering Greece, cats and dogs require health and rabies inoculation certificates issued in the country of origin, not more than 1 year previously for dogs, 6 months for cats, and not less than 6 days before arrival.
• Foreign yachts can buy fuel duty-free, with customs approval, at stations that are marked by yellow & blue diagonal stripes.
• The Greek courtesy flag as well as the Q flag must be flown in the correct manner (position, size, condition).
• A visa is not required for a visit of up to three months for nationals of the EU, Andorra, Antigua, Argentina, Australia, Canada, Ecuador, Iceland, Israel, Japan, Liechtenstein, Mexico, New Zealand, Nicaragua, Norway, St Kitts and Nevis, South Korea, San Marino, Switzerland, Taiwan, the USA and Zimbabwe. Entry may be refused if there are Turkish Cyprus stamps in the passport.

Fees

• All Non-Greek Boats (over 7 metres):
  There is a charge of 5.80 EURO per metre, payable at the first Port of Entry. This is called a “Circulation fee”. If planning to stay in Greek waters 12 months or more, the same fee will buy you a permit called “Private Pleasure Yacht Permission for Stay and Maritime Traffic Document”. It is valid for 3 years and is a single-sheet A4 document.
  In 2002 an additional flat charge of 15 EURO was introduced for actually issuing these permits. This is called the Port Police charge.
  The penalty charge for re-entering Greece within 30 days has been withdrawn, although the “Circulation Fee” will still be due.
  At present there is no further news on what action the EU Court is planning regarding the refusal by the Greek Government to abandon this illegal tax.
• All Boats:
  The third charge is 30 EURO for a DEKPA - Private Pleasure Maritime Traffic Document. This is a 6-page A3 booklet, which must be presented to, and stamped by, the port authority on entry to, as well as exit from, each port visited. It is valid until all 50 boxes are stamped. This charge is applied to all yachts including Greek-flagged ones.
• Non-EU Boats:
  For non-EU registered boats after 90 days, there is a charge of 14.67 EURO per metre and they must obtain a formal “Transit Log”. This charge is levied at the end of each 90 day period, and it appears that if the yacht leaves Greece before the end of 90 days the charge will not be made.
  Possible other charges:
  All public harbours now charge a mooring or anchoring fee based on the tonnage and length of the yacht, usually about 6 EURO for 11m. Boats from EU countries pay lower fees than those from non-EU countries, while Greek flagged boats pay even less. There is a basic fee charged at every port for completing the paperwork. A lower fee is charged for anchoring. In most ports these fees are charged even if stopping for provisions only, or even to buy fuel. Re-launching fee of 7.34 EURO. A fee is charged by customs for each fuel delivery.

Please note that even the Greeks contradict themselves when interpreting these laws. The various guides also disagree at (minor) points, plus the European Union has put a lot of pressure on the Greek government to adopt less protective regulations, hopefully changing regulations in the near future. This pressure was already successful in 2002 and 2004.

Page courtesy of www.sailingissues.com

National flags or ensigns

The vessel’s national flag - not necessarily the same nationality as the skipper or owner - should be displayed at the stern of the yacht; however on traditional yachts, placement on the main leech or gaff is historically more correct.
If the crew’s nationality differs from that of the yacht, the crew’s national flag can be flown under the courtesy flag at the starboard spreader. Likewise the nationality of an important guest on board is displayed this way.
Note that the European flag should not be used, since it doesn’t refer to a nation.
Flag and ensign are synonymous. The name ensign is derived from the French enseigne and Latin plural insignia.

Courtesy flags

When in foreign waters the courtesy ensign, often the national flag of that country, is hoisted under the starboard spreader of the most forward mast. On a mastless powerboat, the courtesy flag replaces any flag that is normally flown at the bow.
Like the national flags or ensigns, the courtesy flag is hoisted at 08:00 local time and lowered at sunset. Yet, when manoeuvring - for example entering or leaving port - the national flags should be flown even at night until your ship is out of sight or safely at dock.

Q flag

The yellow Q flag should be flown instead of the courtesy ensign until the yacht is properly cleared by customs and immigration, after which the Q flag is replaced by the courtesy flag.

Burgee

The - often triangular - burgee from the skipper’s yacht club or sailing organisation is also hoisted at the starboard spreader, but below the courtesy flag. International yacht club burgees are often hoisted above the nationality flags of crew or guests. Yet, purists will say that also crew national flags should be hoisted above any burgee. Too avoid possible insult it is therefore best to fly your burgee below all national flags!
The burgee may be flown day and night.

International code of signals

First drafted in 1855, this visual system was first published internationally in 1857 and gradually adopted by most seafaring nations. The 1932 modernisation allowed for new situations like a medical distress call involving radiation casualties (AN 2). Some other interesting examples: (IT): I am on fire; (US 4): Nothing can be done until weather moderates; (GM): I cannot save my vessel; (NC No and Yes) is used as a distress signal.

Alphabet

A	B	C	D	E
F	G	H	I	J
K	L	M	N	O
P	Q	R	S	T
U	V	W	X	Y
Z

Numerals

0	1	2	3	4
5	6	7	8	9

Repeaters

First	Second	Third	Fourth

Another useful flag

Diver down

Page courtesy of www.sailingissues.com

Short Answer:

British Admiralty charts!

Long Answer:

For safety reasons you should at least have onboard the Greek Waters Pilot or the Ionian Sea Pilot by Rod Heikell together with the accompanying Tetra charts by Imray. Yet, the BA charts are generally much more detailed and precise than the Tetra series.
The Greek charts by the Greek Hydrographic Office are often preferred as well.

Beaufort scale

Specification and speeds Equivalent speed at 10 m above sea level   Mean Limits Description in forecasts State of sea Probable height of waves* metres Force Description Specification for use at sea* knots metres per second knots metres per second * These columns are a guide to show roughly what may be expected in the open sea, remote from land. Figures in brackets indicate the probable maximum height of waves. In enclosed waters, or when near land with an offshore wind, wave heights will be smaller and the waves steeper.

Page courtesy of www.sailingissues.com

The term wind chill goes back to the Antarctic explorer Paul A. Siple, who coined it in a study: “Adaptation of the Explorer to the Climate of Antarctica“.
In 1940 Siple and Charles F. Passel conducted experiments on the time needed to freeze 250 grams of water in a plastic cylinder that was exposed to the elements. The three parameters involved are:

• the initial temperature of the water;
• the outside temperature;
• and the wind speed.

The wind chill factor or equivalent temperature uses a neutral skin temperature of 33 °C as a baseline value, so only two parameters remain. Definition: Wind chill accounts for loss of heat when warm air around a body is replaced with colder air. The factor is an indication of the effect of the combination of air temperature and wind speed on human comfort and safety.

• The ability to forecast wind chill is especially important to yachtsmen since:

• offshore weather forecasts rarely include a wind chill factor;
• both the wind speed and the apparent wind speed are likely to differ from the forecast true wind speed;
• the nature of sailing implies that the duration of exposure to wind chill can not be predicted;
• the threat of hypothermia can be anticipated by using the factor.

Indeed, the wind chill factor is a highly underrated tool to prevent hypothermia and frostbite on board!

• Forecasts made with these equations are reasonably sufficient, though work is being done at this very moment to obtain a better index or factor.

Current inadequacies include:

• the Siple and Passel experiment did not take into account that the water was stored in a container with properties of its own;
• there’s no heat being generated in a water filled object, whereas the human body is constantly generating heat.
• the original experiment uses wind speed at 10 metres above ground.
• the current wind chill index also ignores other environmental factors such as sun shine, air humidity or precipitation;
• the equations are not valid above 40 knots and below 5 knots!

Conclusion: For your safety - even when sailing in the warmer waters of Greece or Turkey: anticipate and use the equivalent temperature to adequately forecast wind chill.

Page courtesy of www.sailingissues.com

What is navigation?

“Navigare necesse est, vivere non est necesse” is latin for: to sail is vital, to live is not. This phrase tells us that both sailing and the “conditio” of positioning are highly intertwined. Indeed, the art of navigation enables you to set a course and sail to your destination by using only nautical charts, a compass and your common sense. The aim of this course is to teach you how to navigate safely while using the minimum of resources: methods that have been in use since the Middle Ages, and are still applied by the professionals. This course greatly extends on - for instance - the ASA courses and gives you the insight and feel of a seasoned navigator.

Enjoy!

This is chapter 0: Use the moving anchor logo on the right of this page to navigate through the course. Alternatively, click on the links below to study the chapters.
Chapter 1 - Positions
Chapter 2 - Nautical chart
Chapter 3 - Compass
Chapter 4 - Plotting
Chapter 5 - Piloting
Chapter 6 - Tides
Chapter 7 - Tide prediction
Chapter 8 - Currents
Chapter 9 - Navigation aids

Math - Running fixes
Math - Distance of horizon
Math - Vertical sextant angles

Compass deviation table
Lunation, phases of the moon

The wind chill forecast
Beaufort wind scale

UK based sailing schools

Page courtesy of www.sailingissues.com

The triangle OBL (see fig. below) can be described in terms of H, α and Distance: Distance = H/tan(α)
The angle in rad. (0-2π) and both height and distance in metres.

• From rad. to degrees: α = A * π/180, ‘A’ being the same angle in degrees.
• To describe angle A in minutes total, then A*60 = a, thus α = (a/60) * (π/180). So, α = a/3438, ‘a’ being the angle in arc minutes.
• FACTUM: tan(x) = x, if angle x is small.

Resulting in (with π = 3.14): Distance (m)= H * 3438/a

• Furthermore, distance in nm. = distance in meters/1852.

Voilà, la very practical equation:

It contains just two approximations, both of neglitible influence. First, we left out the tan function and second we used 3.14 for π.
Please realize that a smaller angle improves the approximation of the tan. Yet, as an opposing effect the instrument error of a smaller sextant angle increases. All in all, the factor 1.856 is not a typo, and just by chance near to the nautical mile: 1.852 kilometres. If you are still reading, you are very brave person and might perhaps agree that it originates from: (60 * 180)/(π * 1852).

So far we considered a perfect triangle (OBL) and forgot that life isn’t always perfect. Height h is usually quite small, but distance SB sometimes is not. This leads to an extra premise, which is seldom mentioned by other navigation textbooks:
Angle OLS should be bigger than 15°.

Page courtesy of www.sailingissues.com

AD = h is the height of eye above the earth.
DO = BO = CO = r (radius of the earth).
Factum: any angle between a tangent line to a circle and the radius of the circle is a right angle.
Since we have a right triangle ABO where AB = d,
AO = h+r and BO = r,
we can find a formula for d in terms of h:
(AO)² = AB²+BO²
(h+r)² = d²+r²
d = sqrt[(h+r)²-r²)],
where r is approx. 3.440.1 nm An example: Let the eye height (h) be 4 meters (= 0.0022 nm); find the distance in nm of the geometrical horizon.
d = sqrt[(0.0022 + 3.440.1)² - 3.440.1²)] ; d = sqrt[11834303 - 11834288]
d = sqrt[15.146] ; d = 3.89 nm (geometrical)

The distance of the visible horizon as found in the table is greater (4.2 nm) due to atmospheric refraction.
The semi-empirical function used is:
d = sqrt[ (2×3440.1xh) / (1852xρ_o) ], where ρ_o accounts for refraction (0.8279).
Next math chapter: Sextant angles

Page courtesy of www.sailingissues.com