Boat Handling

Sailing & Motoring in Fog

By on Jan 5, 2016 in Boat Handling, Navigation, Preparation | 1 comment

Sailing & Motoring in Fog You can only measure the visibility accurately if sailing & motoring in fog when you have another object in sight so assume that it is less than you think. It can take time to ‘see’ another vessel as you may not be looking directly at it when it first appears. Speed in fog You should be able to stop in half the distance of the visibility because a conflicting vessel will need a similar distance to stop. Slow speed is demanded. Keeping a lookout in fog at sea Post a crew member to keep a visual lookout, preferably stationed outside as you will be monitoring the radar and the chart plotter as well as trying to keep a lookout. Using radar at sea Radar is an important aid in fog but don’t expect it to pick up all the vessels around you particularly when the sea may be lively and wave clutter obstructs the centre of the display, obscuring small vessels. Using the autopilot The autopilot can be vital in fog as it avoids you having to concentrate on the steering and allows you to focus on the navigation. Make sure you know where the disconnect button is in case you need manual steering in a hurry. Navigation in fog You will not get many visual clues in fog so you will be heavily reliant on the chart plotter and/or the radar. Use both to check each other as well as the depth sounder. Types of fog Radiation fog is the one you get in the early morning mainly in harbours and it should clear when the sun warms things up. Advection fog is found at sea when warm moist air flows over a cold sea and needs a change of wind or sea temperature before clearing. Sailing in fog Ideally you should not be under sail in fog. You may not be able to manoeuvre quickly, the sail can obstruct visibility and white sails do not show up in fog. Safety margins Allow larger safety margins in fog particularly for making a landfall. Moderate your speed so you can stop or take avoiding action in good time. Make your boat more visible Have...

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Essential yacht tender safety for skippers and crew

By on Oct 7, 2015 in Boat Handling, Practical, Preparation | 1 comment

Essential yacht tender safety – the dangers inherent in using a dinghy to get ashore from a moored or anchored yacht are all too easily underestimated. A recent experience caused me to have a serious think about essential yacht tender safety. Recently I faced the prospect of coming ashore from my mooring in the pitch dark, in wet, breezy conditions with a strong tide running, over a distance of about 300 metres. I was by myself and it prompted me to ask myself before setting off whether it would be unsafe to use the tender or should I spend the night on board? Consider your options Yes, the driest and safest option would have been to stay on board, but I had my wet weather gear and a lifejacket, I hadn’t been drinking and I was confident that my little Zodiac inflatable was up to the job. OK, if the outboard packed up then it would be a challenging row against the fast running tide.  However the tide was coming in so I wouldn’t be swept out to sea and, with wind against tide, there were going to be sharp little waves to contend with. I decided to go for it and quickly got completely soaked by the spray, as did the gear. Finding my way through the boats on their swinging moorings in the pitch darkness was a challenge.  I was greatly reassured to have my truly excellent Exposure Marine X2 torch. I would urge all those who use a tender to buy one – expensive but worth every penny. They are waterproof, lightweight and incredibly powerful. For details see here . There are inherent risks in most boating activities and this includes using a yacht tender to get ashore from a mooring or anchorage. After last week’s soaking, I have compiled some hints and tips about essential yacht tender safety – see below. Essential yacht tender safety : Plan ahead and make notes of the tide state and weather forecast for when you set out and expect to return from a trip. Wear lifejackets, even for short trips. Wear a killcord, even for short trips. Carry oars as back up in case the outboard fails. Carry a means of communication...

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Capsize – understanding the risks

By on Sep 23, 2015 in Boat Handling, Emergencies, Practical, Preparation | 2 comments

A skipper should know how their boat will cope with rough seas. By working within known limits and understanding the risks, then the chances of a capsize occurring are much reduced. Safety is all about improving the odds. When considering the odds of a boat capsizing, knowing the limitations of its design and stability are critical. In order to do this, it helps to understand the basic principles of how a boat remains upright. Basic principles A boat remains upright because of the way its weight and buoyancy interact. The basic principle of buoyancy is that the upward buoyant force on a body immersed in fluid is equal and opposite to the weight of the fluid that the body displaces. The weight of the fluid displaced is known as displacement and the displaced water has an up thrust, or buoyancy, which is equal to the weight of the boat. The displaced water has a central point, or centre of buoyancy, which varies according to the shape of a boat’s hull and keel. The centre of buoyancy is not to be mistaken for the centre of gravity. The weight of a boat is distributed along its length, pushing the entire vessel downwards.  All the weight acts downwards through a central point, or centre of gravity, which is similar to the fulcrum or central point of a seesaw.  All the structure and the distribution of weight aboard contribute to a boat’s centre of gravity. To keep a boat stable in the water and prevent it from toppling over requires the centre of gravity to be low, which is greatly helped by having a deep, heavy keel and an engine below the waterline. Angle of heel If a sailing boat heels over in a strong gust of wind or is forced over by a big wave, then it will right itself once the gust or wave has passed. When a boat is upright then the force of gravity is directly opposed to the force of buoyancy.  As the boat heels over the centre of buoyancy moves outwards and acts as a lever does, pushing upwards with an increasing force. This is fine up to a point, but eventually as the boat continues to...

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ColRegs Rule 14 – Head-on Situation

By on Sep 12, 2015 in Boat Handling, Navigation, Preparation | 1 comment

ColRegs Rule 14: Head-on Situation (a) When two power-driven vessels are meeting on reciprocal or nearly reciprocal courses so as to involve risk of collision each shall alter her course to starboard so that each shall pass on the port side of the other. (b) Such a situation shall be deemed to exist when a vessel sees the other ahead or nearly ahead and by night she would see the mast head lights of the other in a line or nearly in a line and or both sidelights and by day she observes the corresponding aspect of the other vessel. (c) When a vessel is in any doubt as to whether such a situation exists she shall assume that it does exist and act accordingly. (From Nautical Rules of the Road – ColRegs for power boating and sailing – a Safe-Skipper...

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Rig check – how to prevent failure at sea

By on Sep 8, 2015 in Boat Handling, Practical, Preparation | 0 comments

Regular rig checks prevent the risk of mast and rigging failure at sea. This includes regular rig inspections of the spars,  rigging and fittings, especially before a major passage at sea.   Most rig failures are caused by poor maintenance and breakage of the fittings and connectors, especially those that attach the shrouds to the mast, rather than the actual spars or rigging themselves failing. A quick visual rig check is sometimes all that it takes to deal with a potential problem.  However, attention must also be given to reducing metal fatigue through correctly adjusting and tuning the rigging.   Rig inspections A more thorough inspection of a yacht’s spars and rigging should be carried out at regular intervals by a trained rigger, ideally on an annual basis, or as recommended by the manufacturer. It is also advisable to do an inspection before a major sea passage. The inspection will comprise a visual inspection, sometimes aided by ultrasound tools, where wear is recorded and monitored for future inspections. The inspection will look for items such as cracks in rigging components, misalignment of stays and corrosion. Rig tensions should be checked and adjusted as necessary. A written record should be completed listing existing or potential concerns. Every 5 years or so, more thorough rig checks should be carried out, which involve disassembly of the rig. This may include Dye Testing or Liquid Penetration Inspections which reveal surface flaws not visible to the naked eye. Here’s a useful checklist of things to look out for that we’ve put together with the help of the KZ Marine Group in Auckland, New Zealand: Checklist Deck check – split pins, adequacy of threaded fittings, chafe or breakage of stranded wires, rig cracking, rust streaking, condition of mast collar sheaves, halyard alignment, halyard chafe guards, forestay condition. Masthead – halyard sheaves rotate freely and are sound, bushes, split pins intact, electrical wires are clamped correctly and are chafe free, lights are operating, halyard shackles in good condition, Windex and wind gear operating correctly. Forestay – roller furling headstay, halyard leads at correct angle to swivel car, inspect halyards for wear on sheaves, fairleads and check swivel cars, mast tang pin hole, corrosion around mast tangs, threaded fittings,...

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How to predict wind direction and strength by reading a weather chart

By on Jul 16, 2015 in Boat Handling, Navigation, Practical, Preparation | 0 comments

Weather charts, also known as surface pressure or synoptic charts, contain a lot of information that helps weather forecasters make predictions about the weather and sea conditions. Before going to sea it is always a good idea to study weather charts and work out how the weather is likely to evolve in the area you plan to sail in. This sequence of four synoptic charts predicts the weather over a 36 hour period. Isobars on a weather chart The circular lines are isobars, similar to contour lines on a land map, and join areas of equal barometric pressure.  Air moves from high to low pressure and when the difference in the pressure is greater, the airflow or wind will also be greater.  Isobars that are close together indicate stronger winds. Isobars that are further apart indicate lighter winds. The wind scale inset in the top left of the chart helps you to forecast wind speed. Wind direction In terms of the wind direction, in the northern hemisphere air moves around high pressure in a clockwise direction and low pressure in an anticlockwise direction, so isobars on a weather map indicate the direction and speed of the wind as well as the pressure. Fronts The lines with triangles and semi-circles represent fronts. Warm fronts on a weather map are shown with semi-circles and cold fronts with triangles. The way in which the semi-circles and triangles point shows the direction in which the front is moving. Occluded fronts and troughs Where a cold front and warm front meet an occluded front is created, shown by lines with overlapping semi-circles and triangles.  Black lines with no semi-circles or triangles are troughs and show areas where the air is unstable and showers tend to form. It is a good idea to print out the latest weather charts for your area before you set sail and refer to them on your...

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