Monday 25 January 2010

Sailing by the Stars - How the Ancient Sailors Did it

Technology is fantastic and with the plethora of electronic devices available today for sailors to find their way evermore easily, one wonders where it is going. There have been huge strides in recent years in navigation, radar, chart plotting, global radio contact, weather software programmes, proximity alarms etc.. It is there, available, easy to use so why wouldn't you use it?

But, like motoring, where there are so many devices now built in and attachable in cars that the question has been raised recently if there are so many distracting devices in a car (mobile phones and GPS being the main offenders) that the focus is being taken away from driving.

I wonder if this is happening also in sailboats? Earlier sailors such as the Smeatons, Sir Francis Chichester and certainly Captain Joshua Slocum would have eschewed (albeit they weren't available) them and went on to achieve fantastic conquests regardless.

The ancient Polynesian sailors colonised virtually the whole area of Polynesia in their ocean going canoes with just knowledge that the 'Navigator' carried in his brain and no instruments whatsoever.

The following is an extract from my ebook "Voyage of the Little Ship 'Tere Moana'.

.....'Sunday morning climbs up over the horizon and brings her captain, rising from his bunk, with it. WK stands on no ceremony, and her captain is met by the open case of his sextant on the chart table.

WK has brought his own with him, and is fiddling with the settings on both. Throwing a wolfish grin in his direction, our captain understands what is in store for him this morning. Navigation by the stars has a fascination from time immemorial.

The Polynesian and Micronesian sailors did it the best and were able to successfully navigate thousands of miles of open sea to arrive at their destinations. Very often, these were small lumps of land, or clusters of islands, that could be very easily missed. Many times, of course they did miss, and nothing more was ever heard of those unfortunates.

However, when you consider that all they had to guide them were the stars and a mind map of them, this form of navigation was amazing in its skill. Good navigators were revered. They developed what is referred to as a ‘Star Compass’ or ‘Star Map’, and this was retained in the navigators head. To know all those stars and maintain a course for thousands of miles according to the stars’ position in the night sky, required a consummate skill and a mighty store of knowledge.

An interesting anecdote is the way they expressed the coming and going of the stars. The east, or the beginning of the night was known as the ‘arriving’, because that was where the stars arrived for the night, rising from the horizon. The west on the other hand was known as the ‘entering’ because that was the point where the stars at nights’ end, entered into the sea.

An accurate mind map of the stars is all very well, but it is still a mystery how these ancient and courageous seafarers calculated their position of longitude. There are many theories of course, as there always will be in matters of this nature. One, which would seem to hold water better than most is based on the premise that back then, there was very little else in the way of man made distractions to fuzz the focus of a clear mind.

Metal was not widely used, and there was no radio disturbance, electrical appliances,
motors of any kind, or any of the other mechanical or electrical devices known to man today. Not having any of these distractions cluttering up the ether, our navigators and people in general were far more closely aligned with nature. So much so, that it is theorised that a natural man, standing in the fore peak of his craft, or lying in the bottom/bilge could actually sense the magnetic fields of the planet, drawing him on to wherever there might be land, somewhere in front of his vessel.
In addition the master mariner used all other resources to hand such as the wind, stars of course, wave direction, currents, swell movement, flotsam floating by, bird flight habits, other sea life and many other natural phenomena that was available to him.

They also carried frigate birds on board for use when they estimated landfall maybe not too far away. Frigate birds cannot get their feathers wet as they cannot fly wet, so on release they flew in the direction of land or, if no land in sight over the horizon, they would return to the canoe - hence the frigate bird image in the centre of the 'star compass' shown.

Noon clutches the sun precisely at its zenith – one minute before and it is rising yet, one minute after, it is already on its way down and setting. For practical purposes, the closest to noon a sight can be taken the better, but a minute or two either way can be allowed for in the subsequent calculations. Many things can get in the way of capturing the sun in the mirrors of the sextant, and tamed, dragging him down to the horizon exactly at midday – mirror not adjusted correctly, clouds over the sun, a sudden lurch of the boat, fumbling fingers – all can impede, and once done their mischief can take a few moments to salvage.

Our stalwarts manage a good sighting, with the lower limb of the sun, drawn down, lightly kissing the horizon, straight off. Notating local time and GMT(UTC/ZULU), they race below to fix their position. Until recently these calculations were made by using a complicated set of ‘declination tables’ and took some time to arrive at an accurate answer. Apart from this, they were bulky and heavy. With the arrival of the space age which has given us GPS, it has also brought us a astro navigation calculator which, with a few simple paths to follow, will give an accurate position from the information gathered up on deck.

Our crew race one another to punch in this data, read off their results and then compare them with the GPS, which of course is one hundred percent accurate. To their surprise, they are within 1.5 to 2 nautical miles of the GPS position stated. This is very good and certainly good enough to know exactly where they are at any time on the oceans of the globe. With a certain amount of glee they pronounce that tomorrow they will get even closer.'

Extract from my ebook 'Voyage of the Little Ship 'Tere Moana'

An interesting website dealing with this subject in more depth is 'Polynesian Voyaging Society'

You can read more about navigating under the stars in my ebook 'Voyage of the Little Ship 'Tere Moana' downlaodable from my website

Thursday 14 January 2010

Sailboat 'Rafting Up' for Yachtsmen

'Rafting Up' in sailboats is a temporary action when moorings are not available, meeting friends, a short stay for lunch or assisting another vessel with some technical problem or other.
It is certainly not recommended for overnight staying unless you are in a very shelterd position, the other craft is securely anchored and the weather has been thouroughly checked. Even then it is better to stand off and anchor apart.

The following is an extract by Mark Matthews is from Sailnet Community and gives some good tips on how to proceed:
Picking Your Spot Rafting up is best done in sheltered waters, in the lee of the prevailing wind, and out of the way of harmful boat wakes. Think millpond. The best approach, if possible, is to raft up to a boat that is already
securely anchored. If you're the raftor (the boat joining a stationary vessel), come to a stop along side the boat—roughly bow to bow—and heave both bow and stern lines so that you can draw the boats together in the most controlled fashion. (You can run spring lines immediately after the others are secured.) This will allow all parties involved to fine-tune and tweak the boat placement as the boats come together, adjusting lines and fenders as necessary. This approach will also minimize the chance that an over eager crew will put his or her finger or toe in between the two boats at the wrong time. Remember, boats are heavy, and bringing them together slowly is always the best approach.

Of course one of the keys to a successful raft up is to recognize the differences between the two boats involved, paying careful attention to what is happening overhead. Be sure to stagger both boats so that the rigs (mast, spreaders, etc.) can't make contact should the boats start rocking from wakes or waves. And if there's to be a third or fourth boat joining the raft up, make sure that the rigs of those vessels are staggered as well. (Ideally the largest boat in a multi-boat raft up will occupy the center position, with its anchor firmly set.)

Fenders and Lines In any raft up, fenders are likely to get a good workout, and usually, the more protection each party can put over the side, the better. Of course placement is critical. With the boats staggered, you want to make sure that the majority of your fenders are used along the larger boat's central section. You'll also want to deploy one or two safety fenders fore and aft of where the others are concentrated just in case a large boat decides to cruise through your anchorage at full speed. Veteran cruisers know that these incidents happen, but little can be done after you first sight a small tsunami making its way toward your raft up, so plan in advance for exactly such an event.

When rafting up alongside larger vessels, it's best to use oversized fenders.

Lines likewise need to be run fairly and should be attached to stout end points. Cleats and winches are acceptable, while most stanchions are better left out of the equation. Because these lines will be under strong loads, you should use only knots that have proven themselves through maritime history, and leave the creative macramé for tying down luggage to the roof rack of your car. To make life easier for stepping from cockpit to cockpit, make sure the spring line from the stern of your boat is led forward of the beam on the boat you're rafting up to. Once you tighten this, is will bring the cockpits closer together and leave both bows pointed out just slightly.

Anchoring Etiquette Generally speaking, it's better to have the smaller boat raft up to a larger one that is already anchored. A smaller boat is likely to be more maneuverable than a larger boat and easier to pull alongside and the larger boat will most often have the larger ground tackle. The larger boat should set its ground tackle with more scope than it would if it were simply anchoring alone.

There are an infinite variety of situations that may call for bow and stern anchors, or even a kedge. The mothership in the raft up may have an anchor out to an iceberg or one that's wrapped around a palm tree. Nonetheless, the crew of each vessel in the raft up should be ready to cast off quickly should there be a change in the weather or other alteration to the conditions in the anchorage. Every anchorage is subject to a number of variables, so it's best to keep an eye not only on weather conditions, but the strength and state of the current, the tide, and the activities of other boats in the vicinity, and act accordingly. If you're rafted up in a marina on an outside dock, for instance, and the current is pinning you to your host, you may want to consider setting an anchor amidships, if there's room, to keep you from squishing the fenders into oblivion.

Now, if your boat is the mothership and everyone else is rafting up to you, this is no time for a lowly lunch hook. Set you biggest anchor, and set it well. If the raft up that you're involved in is approaching Guinness Book of World Record proportions, the boats on the end should each run out an anchor at a 45-degree angle and all the keels should be kept parallel. In large volume raft ups, try to keep a coherent and consistent system among all the boats, with all the lines run in the same way. If all the participants tie up in the same way, it allows a quick escape should the need arise.

Apart from raft ups made necessary by transiting locks and over-crowded marinas, most raft ups are more the product of celebration than utility. But just because you and your crew haven't seen s/v So and So since the Battle of Trafalgar, that doesn't give you an excuse to tune out the weather. Indeed, there are probably few better times to pay extra attention to the weather than when tied alongside another boat, especially if you're going to be rafted up for more than a couple of hours. Make a mental note somewhere in your cranium that the shorter the duration of the raft up, the less likely you'll be awoken by several thousand pounds of lead, fiberglass, and aluminum clashing.

Common Courtesies Space aboard most any boat is always an issue, particularly personal space. So even if you've been best friends with the boat owner since third grade (and doubly so if it's someone you just met), make sure you respect the privacy of the boat you're rafted up to. Most owners would rather you tip toe through their boat's cockpit than stomp over the v-berth on the way home from the local watering hole. If the boat is a center cockpit design, it may be better to walk around the stern to get to your vessel. You'll have to use your own sense of judgment in these situations, but it sure wouldn't hurt to ask the owner of the boat you're rafted up to beforehand what he or she prefers.

In the best of all possible worlds, a raft up is usually a temporary event, done in good weather and benign conditions. Done well it can offer you the chance to check out boat differences and similarities up close and personal, or allow you to get reacquainted with old friends or make new ones. Done poorly it can leave you and your boat smarting from dings in the topsides, or worse yet rigging damage. But by keeping in mind a few simple steps, coupled with some common sense, you can ensure that rafting up is a positive experience, allowing you and other sailors to broaden your cruising horizons.

Extract and images courtesy Sailnet community, Mark Matthews and Kathy Barron

In an earlier blog (13 november 2009) I talked about Egmont Friedls' knot tying DVD - in that is a very good subsection on coiling and casting a line for rafting up and belaying/tying up to cleats and bollards. You can find him on

You can read more about rafting up and friendly encounters whilst cruising, in my ebook 'Voyage of the Little Ship 'Tere Moana' downloadable from my website