Yacht Engines

The most dramatic of the remarkable revolutions in yachting brought about by the great technological advances of the second half of the twentieth century is the establishment of the light, totally reliable diesel auxiliary. Gone are the days when we pressed the starter button, hand in mouth, more in hope than in expectation. The petrol marine engine with its vulnerable electrics and lethal fuel is in full retreat. It may be cheap, and it does weigh next to nothing, but its vices are no longer...

Classical Position Fixing

In the last chapter we noted that the navigator of a yacht is constantly estimating his position, and that this may be done informally, even subconsciously, or formally on the chart. From time to time, the need arises to check the accuracy of these estimates, either because you are in the vicinity of a danger, or because you need a known point of departure for the next leg of the passage. This is done by fixing your position. There are any number of ways of producing a fix, including...

Frontal anatomy

The boundaries of the warm sector of a depression are marked by a warm front on its leading edge and a cold front behind (Fig 31.3). As a warm front moves along, it pushes across the upper cold air first and gradually comes down to sea level over a width of anything up to 200 miles. The first visible evidence of a warm front arriving is the presence of high 'mare's tail' clouds known as cirrus (Fig 31.4). These are followed by a layer of thin cirro stratus cloud which often begins by generating...

Tactics and Navigation in Heavy Weather

In Chapter 10 we considered the main survival options open to the average yacht caught in deep water by weather of sufficient severity to demand a change of voyage plan. To recap, these were heaving to, lying a'hull, running off and working to weather under power-assisted sail. Which, if any, of these you choose to adopt on a given occasion will depend upon your position in relation to land, or any other relevant danger, the type of craft you are sailing, and the strength of your crew. At the...

Secondary ports

The one small fly that remains kicking feebly in the ointment is the old favourite of secondary ports. The system for working these out probably can't be improved upon. Just work out the rime and height of High or Low Water for your secondary port and enter it on the diagram exactly as above. If you are operating in the areas adjacent to and including the Solent you'll find that, because of the tidal anomalies causcd by the Isle of Wight, several extra sets of curves arc supplied for the...

Tidal gates

Even in areas where the currents are generally weak, if there is any rise and fall of tide to speak of, places will emerge where the current becomes a significant factor. Where streams along the coast are strong in any case, salient headlands and narrow channels may produce violent currents for the mariner to contend with. Such places are known as tidal gates and it is important to time your arrival at them either for slack water if the sea is known to become dangerously rough, or for the...

Coiling

All three-strand ropes arc right-hand laid. As a result, they coil clockwise. Cable-laid hemp hawsers didn't, but I haven't seen one of those on a yacht since 1969, and then it was so old it snapped under the most modest of loads. Try to force a right-handed rope the other way and it will hate it. So will you, especially when it runs off the coil in a scries of block-shattering kinks. You shouldn't have it in you to coil against the lay, whether you are tidying up your washing line or coiling a...

The trailing log

These mechanical devices, still used by some yachts (including my own), are a major step up from the old 'log chip' arrangement. They work by towing a 'fish' shaped so that it will rotate at a known rate, from a simple analogue measuring device attached to the aft part of the vessel. Distance run is usually measured, realistically, to the nearest 4 mile. These instruments are reliable and accurate. If yours over-reads or under-reads it will at least be consistent, so that once this is known,...

Fouled anchors

So long as it stays shackled to its cable, which it will it you have wired the shackle properly, there are only two things that can go wrong with an anchor on the seabed. It can become fouled, either by its own cable around a spare fluke (as can happen with a fisherman) or by some foreign body neutralising its effectiveness (such as a large baked-bcan can impaled on the fluke of a CQR). These difficulties, together with excess of seaweed, will cause the anchor to fail in its duties. The only...

Safe track

Two types of line are essential to the business of pilotage (Fig 23.1) the safe track, which is the straight line leading through a particular set of dangers and the clearing line, defining the edge of a danger area. Keep on the right side of a clearing line and you are safe venture across it, and you are stranded. Fig 23.1 Safe pilotage. Above a safe track. Below a clearing line. Fig 23.1 Safe pilotage. Above a safe track. Below a clearing line. Planning is vital for close-in pilotage because...

Evaluation of fixes

Only you know how good a PL is likely to be, because you took it. If you have three winners and the result is a tight cocked hat, you can be confident of your position, particularly if the echo sounder backs it up. If your input data is not so surefooted, you'll have to treat the results more carefully and plan your immediate future accordingly, always erring on the side of safety. The essence of navigational security is to take your information from more than one source whenever possible, so...

The log book

In an ideal world, the textbook navigator plots his EP every hour during an offshore passage. In reality, you sometimes do it more often, sometimes less, depending on the need of the moment. It is therefore most important that all course changes are logged together with times and log readings. EPs should be logged, so should fixes, objects abeam, electronic plots, and any other significant navigational event. Even if you've plotted nothing on the chart, there should be enough information in...

Pyrotechnics

They are, however, expensive to buy and since you hope never to use them, it comes hard to spend more than you must. The answer for the thinking boatowner is therefore to ship a complete outfit of up to date flares and smoke signals, but to keep your older ones aboard as well. Unless they came from HMS Victory, there is a good chance that they will work. They could save your life. Red rocket (parachute) flares are used to indicate that there is a vessel in...

Chart projections

Certain compromises must be made by the cartographer to deal with the inconvenience caused by the world being more or less round, while the chart is necessarily flat. Generally, these arrangements distort the coastline. On world-sized maps, they can give rise to gross misconceptions about the relative size of land masses in different latitudes, but, as we shall see, there are useful trade-offs for these drawbacks. The Mercator projection is the most usual chart form for coastal and offshore...

The running fix

When you have only a single known charted object to go on, and no means of determining your distance off, you can still fix your position with a running fix. A typical situation is when you are passing a singleton lighthouse in the dark (Fig Take a bearing when the light is about 45 on the bow. Note time and log reading and plot your bearing. Wait until you have run far enough for a good 'cut', then take a second bearing, noting time, log and depth. Plot the PL. Transfer the first PL up to an...

Air circulation

A person standing at the Equator is actually moving very quickly relative to the space above him, with the turning of the Earth. An explorer stationed at the Pole isn't moving in any direction at all. Instead, he is pirouetting like a skater in a slow spin, executing one revolution every 24 hours. If the sun-lover careering round at the Equator could hurl a ball far enough to get anywhere near the polar explorer, it would not arrive becausc it would carry with it a component of its original...

Variation

If you don't have a pictorial mind, you may prefer one of the standard aides-m moires. My favourite is Error West, compass best Error East, compass least For 'best' read 'biggest', and you have a foolproof system which conforms perfectly to the diagram. If the compass is 'best' with the error on the west side of true north (magnetic greater than true), it follows that the true heading will be less than the magnetic, should you be converting that way. 'Error East, compass least' (magnetic less...

Deviation

The other major factor affecting a compass is deviation. This is an error originating from within the boat. Any ferrous metal affects a compass to a certain extent. If it is too close (say, either 4 or 5 ft in a horizontal direction) the results will be noticeable. Deviation, unlike variation, is not only undesirable, it can be minimised by your own efforts. Site the steering compass intelligently and don't leave screwdrivers, battery driven appliances, radio speakers and other magnetically...

Charts required for a passage

A passage chart should be used to determine overall strategy and courses to steer. Ideally you should find one which covers the whole trip, because trying to move a course from one to the next is never easy and can lead to errors at sea. Landfall charts giving enough detail to approach the coast are required for your departure point, your destination, and any other part of your passage which may bring you close enough inshore to need them. If you are unfamiliar with the harbour of your choice,...

Under power

Nowadays most people anchor under power. First, the boat is headed up to the wind, the tide, or to seaward if she finds herself in an open roadstead where an onshore breeze may become a contingency. As soon as she has lost way over the (Note the useful transit to check the anchor is holding.) (Note the useful transit to check the anchor is holding.) ground, the anchor is dropped, or lowered if it is light enough. When it is on the bottom, the run of the cable is checked and the boar is steered...

Chart datums

Most charts carry a statement concerning the datum to which they are constructed. This is nothing to do with the Chart Datum for depth soundings referred to above. It is a convention concerning the pinpointing of position. Because inaccuracies caused by ignoring it are often much less than a cable's length (200 yards), it has only become relevant with the arrival of electronic fixing aids. Numerous datums are used worldwide. The UK was for many years OSGB36. Europe was ED, while much of the US...

Radar bearings as position lines

Most radar sets have an electronic bearing line (EBL) running from the centre of the screen to its edge. This can be rotated until it touches the image of an object you have identified on the chart. The bearing can be read off from a digital display. If your radar gives a 'head-up' picture (ic the top of the screen is where you are headed), this bearing will be relative to your yacht's heading. To convert an EBL reading on a 'head-up' set to a compass bearing, you have merely to add the...

The beam sea

In many ways this is the worst condition for all boats. As we'll see in the Appendix, the beam sea is the thing to be avoided at all costs for many craft in survival conditions. Before such extremes are reached, however, a beam wind is a fair wind and you won't want to waste it. The problem of the beam sea is that the big, steep waves pick up your boat and hurl her down into the trough. This is wet, unpleasant, and can cause structural damage on the lee side of the vessel. Large cabin windows...

Towing

Ideally, you should attach a tow rope to the towing vessel in the vicinity of her pivot point. Only in this way can full manoeuvrability be retained. If you are supplying the tow with your yacht, this is probably going to be impossible, because of your backstays and the general lack of strong points in the desired area. Towing is therefore best done from the stern, but it must be from the centre. You are usually left with no choice but to rig a strop between the quarter cleats or fairleads and...

Sectors and obscuring lines

Some lights arc only visible within certain angles, owing to their being obscured beyond that by a hill, a headland, or some other feature. This is usually, but not always, noted on the chart. Certain light structures shine different colours into different sectors of their approaches. This is generally used where a specific danger is present whose sphere of influence is defined by a red or a green sector. The coloured sector light may be independent from the main light of the structure in which...

Boat Handling under Power

As soon as you install a propeller on a boat, you enable her to do two things which she cannot do under sail. She can make way for an unlimited period into the eye of the wind or in no wind at all, and she can stop more quickly than ever she could by virtue of the natural forces which otherwise prevail. It so happens that these two items are often critical, particularly the former. They enable an indifferent power-assisted seaman to succeed where the finest sailor in the world could resort only...

Boat Handling under Sail

If you are a comparative newcomer to the world of sailing, you may think it odd that a chapter on handling under sail should precede one explaining how best to benefit from auxiliary power. Should you have come to cruising from dinghy sailing, however, it will seem entirely natural. There are even a few of us left who learned our sailing in cruisers without any power unit at all, save a sweep or a quant pole. In fact, sailing a yacht of moderate tonnage in close quarters can be as easy as...

Ropes and Ropework

Today's yachts arc such marvels of technical sophistication that they only really have two things left in common with craft from the days of Noah. Both float most of the time, and both use rope. Rope has been the primary tool of the sailor since the dawn of sail. The material from which it is now constructed, however, would be unrecognisable to a sailor of even the mid-twentieth century. The natural fibre ropes, now consigned to history, deteriorated after a short life through a rapidly...

Radar

Radar is the most interactive aid to navigation. Using it properly demands far more expertise than an electronic fixing aid because its readout comes in the form of a picture which, to the uninitiated, is hard to interpret if not incomprehensible. Buying a radar set, therefore, does not solve all your navigation problems. Nonetheless, the rewards are great for those who persevere, because radar indicates visually many of those things the navigator would like to see with his own eyes but cannot...

Leeway

Any boat sailing with the wind on or forward of the beam makes leeway (Fig 17.1). In fact, she makes it all the time except when the wind is dead aft, but it becomes much less significant once the wind is abaft the beam. How much leeway you make depends on the boat, the wind and the sea. A powerful 40 ft (12 m) cruiser hard on the wind in force 4(15 knots) and a calm sea makes only 2 or 3 , while a 22 ft (6.7 m) bilge-keel yacht trying to hack to windward in force 6 (28 knots) could be sliding...

Food

The most important items for crew morale are food and drink. Whatever horrors are coming to pass, if the team know that they will be fed and watered appctisingly and on time, you are at least half-way to a happy ship - and a happy ship is usually an efficient ship. The galley should be set up so as to make this requirement realistic to fulfil. On passages of more than 12 hours, this becomes vital, but even with poor cooking arrangements, there are certain precautions which can be taken to make...

Securing to a cleat

There are various seamanlike ways of securing to a cleat. The important thing is to ask yourself Is the way I am doing this absolutely foolproof against jamming or locking up, and will I be able to ease the rope away under control if I want to Answer 'yes' and you are doing it right. It's important to lead the rope properly in the first instance (see photographs) or you are on a loser. Once the first half turn is on, plenty of figures-of-eight works well, though some folk prefer a fiill round...

Lighthouses

A lighthouse or a beacon is indicated on the chart by a star which marks its accurate position. Your attention is called to the fact that it is highlighted by a magenta 'flash' shaped like a lozenge with one end pointed. The sharp end is hard by the object it refers to. Adjacent to the star is all the charted information about the light. Any further and better particulars, including a physical description of the structure, will be found in the officially published List of Lights. A light is...

The GZ curve

Under theoretical conditions, a vessel's ability to stay 'on her feet' arises from two basic forces the form stability which she possesses by virtue of her beam, and the pendulum effect of her ballast. The results of form stability are noticeable at relatively small angles of heel, while the righting effect of a ballast keel is at its greatest when the boat is on her beam ends. For a yacht to be properly seaworthy, her stability must stem from a healthy combination of the two. When a yacht...

Basic Seamanship under Sail

If you were looking for a definition of seamanship, you could say that it is the art of making the sailor's skills look easy. It is tempting to imagine that a simple task like winding a sheet in on a cockpit winch will be much the same under any skipper, or that heaving down a reef is a nuisance whoever is driving the boat. In fact, neither proposition is true. One master may soak a foredeck crew while they arc changing a headsail another will go out of his way to keep them dry and safe. The...

Transferred position lines

Occasionally, you find yourself in need of a PL which runs in a certain approximate direction and no obvious source presents itself. In these circumstances you can sometimes utilise a PL taken fairly recently by 'running it up' to your current position. This is done by assuming a position on the old PL, then plotting a current EP worked from that assumed position. The PL is now transferred as a parallel line that cuts the new EP. It is labelled with two arrowheads at its end (Fig 18.6)....

Theory of Sailing

I had been sailing for many years before my first opportunity arose to skipper a powerful motor boat. She was not fast, but she was seaworthy and had a more than adequate supply of horses harnessed to the inboard end of her propeller shaft. Making passages in her was a revelation. I could shape cross-tide courses accurately because my boat speed was a known factor. ETAs could be predicted with uncanny accuracy by simply dividing the distance to run by the number of knots I had decided to dial...

General functions of chart plotters

The biggest problem with chart plotters is scale. If you can see enough of the chart to achieve an overview, you don't have enough detail to see what you're about to hit. This is dealt with by zooming in and out, and panning across the chart. Learning how to do this is not only a physical process, it also requires a jump of consciousness for anyone brought up on paper charts. Larger plotters can actually be used exclusively by a skilled operator always given paper backup , but small-screen...

Forestay or backstay failure

A mast may be in dire straits following the loss of a shroud, but when a forestay or a backstay carries away it will be lucky to survive. There is, however, a slim chance that if the backstay lets go, the combined effect of the lower shrouds and the leech of a closehauled mainsail will hold it up long enough for the crew to act. Similarly, a damaged forestay may be covered for a few moments by the luff of the jib, or a halyard stowed on the pulpit combined with a baby stay, but the only real...

Spring and neap curves

Noticc the 'mean range' box at the top right-hand corner of Fig 14.4 giving spring and neap ranges, with a firm and a pecked line depicted alongside it. The tide curve with the solid line is the curve for spring tides and that with a pecked line is for neaps. You can ascertain rapidly by inspection whether today's tide is a spring or a neap, or somewhere near. If it falls between the two, you will use an imaginary curve between the solid and the pecked ones. This can easily be done by...

Fog signals

Many lighthouses and some buoys carry a fog signal, activated when the visibility falls below a critical range. These are highly reassuring to any mariner, particularly a non-electronic one, or one who wisely chooses to seek confirmation of his position from beyond the confines of his 12-volt electrical system. There are various types of fog signal, listed below. All have their own distinctive sound. They are indicated by type on the chart, which will also show any time sequence, eg Horn 60s...

Coming alongside

The chances are that your crew will be less experienced than you. Watching someone who doesn't really know what to do step ashore with a dock-line is rarely edifying. It's up to you to tell the hands what is required. Here is a rule-of-thumb method for a fully crewed boat. It covers most regular situations State 'which side to', and rig fenders. Don't put them over until you're nearly there, though. Nothing looks more sloppy. Prepare all four dock-lines. Have two ready for instant action. Lead...

Creative use of GPS in tidal stream deduction

A final source of tidal stream information is your electronic fixing system. The difference between a dead reckoning position corrected for leeway Chapter 17 and a GPS fix is the set and drift experienced since the last plotted position. Alternatively, you can compare the GPS 'course and speed over ground' COG and SOG readouts with the compass heading and logged speed. The onboard data which the latter pair supply can only be measured through the moving water, while the GPS information is...

Depth soundings

Wherever the bottom is of such a nature that it forms clear contour lines, your echo sounder is a source of PLs. Reduce the depth to soundings, then inspect the chart. Your PL is the relevant contour, none the worse for not being so straight as a transit Fig 18.4 . If your depth places you between two charted contours, you'll have to judge where yours is most likely to be. The nature of things is such that contours are rarely so precisely defined as a transit leading mark. Even if your PL is...