Select Page

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.

038_Met 5

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.

038_Met 4

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.

038_Met 3

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.

038_Met 2

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 trip.

Safety Equipment Checklist for Boats

Safety Equipment Checklist for Boats   Liferaft line attached The liferaft will not work unless the trigger line is...

Saildrive maintenance

There are less maintenance tasks to carry out on a saildrive transmission than on a traditional inboard shaft drive system with its associated stern gear. However, there are a few critical things that require maintenance, as recommended in detail by the engine manufacturers, and should be adhered to.

First Aid Afloat – fish spine injury

First Aid Afloat - Here is what to do if somebody stands on a fish spine: • Check for dangers. Is it safe for you to enter...

Cleaning & polishing gelcoat topsides

The gelcoat topsides of a GRP boat can be pampered and restored to their former glory relatively easily when it is ashore. Gelcoat is only a very thin outer layer of the hull, often less than 1mm thick, so you should avoid cleaning it with highly abrasive cleaners, or an-ything that could potentially damage its surface.

Electric motors and hybrid systems

In recent years there have been considerable advances with the development of electrically powered propulsion in the leisure marine sector. This includes developments with inboard and outboard electric motors, hybrid systems, lithium-ion battery technology as well as solar, wind and hydro powered generators.

Navigation safety: a quick-reference mobile app to learn the ColRegs NavLights and Shapes

 Safety at SeaSafety at sea will always remains a topical and important subject that will no doubt dominate the syllabuses of nautical...

Points of Sailing

The course on which a boat is sailing can be described by its angle to the wind, not to be confused with its compass...

ColRegs when sailing single handed

  Don’t neglect the Colregs when sailing single handed Sailing single-handed represents several challenges for skippers, not least how to...

Boat interior inspection and checks

While a boat is ashore, the most critical interior checks to carry out are those that concern the safety of the boat. This entails the integrity of all through-hull fittings and seacocks, the gas system and the electrical system.

Avoiding collisions at sea – how to stay safe on the water

Boats have many blind spots, including the headsails of sailing boats. Always keep a lookout, stay safe and remember that...

Antifouling for leisure boats – Part 2

To prepare for antifouling, as soon as your boat has been lifted out and pressure washed, you need to check all the surfaces of the hull below the waterline, remove any remaining barnacles and check for blisters.

Cleaning & polishing painted topsides

The gelcoat topsides of a GRP boat can be pampered and restored to their former glory relatively easily when it is ashore. Gelcoat is only a very thin outer layer of the hull, often less than 1mm thick, so you should avoid cleaning it with highly abrasive cleaners, or an-ything that could potentially damage its surface.

Seacock maintenance

If seacocks are always left open and neglected they can eventually seize which will prove a serious threat to boat safety should a connecting hose fail and the seacock refuses to close. There are three main types of seacock – ball valves, cone valves and gate valves.

Essential yacht tender safety for skippers and crew

Essential yacht tender safety - the dangers inherent in using a dinghy to get ashore from a moored or anchored yacht are all too easily...

Essential Boat Safety Briefing

Skippers Responsibilities Skippers are obliged to give a safety briefing to the crew even if they are a regular crew. At...

Sector lights, directional lights, leading lights – how do they differ?

Sector lights, directional lights and leading lights guide vessels safely through hazardous waters or narrow channels at...

First Aid at Sea – strains and sprains

Strains and sprains respond well to rest and cooling. Wrap ice in a tea towel before applying. First Aid at Sea Strains and...

Safe Skipper – crew management tips

Effective crew briefings are a vital part of the good on-board communication that helps everything to run smoothly on a sailing vessel at sea, whether it is cruising or racing.

Capsize – understanding the risks

A skipper should know how their boat will cope with rough seas. By working within known limits and understanding the risks,...

Passage planning and pilotage

Passage planning and pilotage help skippers navigate safely from one port to another. A passage plan takes into account all...

The VHF DSC Radio jargon buster

AIS - Automatic Identification System This system is used by shipping. It allows another vessel or coast station to use...

Boat maintenance log

Keeping a boat maintenance log is an ideal way of reminding owners what needs to be done to a boat and when. Read on for some tips,...

Antifouling for leisure boats – Part 1

Boats that are kept afloat can very quickly become a home for small marine organisms such as barnacles, weed and slime. Applying an antifouling paint to your hull is necessary to protect it from these micro-organisms, as a fouled hull can cause problems and will slow down a boat’s maximum speed considerably if left unchecked.

The give-way hierarchy at sea – who gives way to whom?

Whatever their size or type, all skippers have a responsibility to avoid collisions with other boats at sea.  It is...

Marine engine electrical system

The typical basic electrical system associated with a marine engine includes a dedicated engine starting battery, a starter motor, a charger in the form of an alternator, a solenoid and some engine sensors and instruments.