Understanding how to read nautical charts is one of the most important skills for safe sailing. These special maps are packed with information about water depth, hazards, landmarks, and routes. In this guide, we’ll break down the essentials so you can confidently plan and navigate your sailing trips.
​

Some Electronic Charting Tools

Many sailors today use apps or chartplotters with GPS:
• Navionics (available in UK/USA)
• iNavX
• Savvy Navvy
• OpenCPN

These apps provide live tracking, tide data, and automatic route planning. But don’t rely solely on tech—always carry a paper chart and compass as backup.
​

• Upwind: Sailing toward the wind (you can only go at an angle)
• Downwind: Sailing with the wind behind you
• Beam Reach: Wind comes from the side

Adjusting your sails based on the wind direction is called 'sail trim'. The better your trim, the faster you sail.

Step 3: Safety First
​
Of course, you are not going to go sailing on your own or without a competent companion. But even if it's just to make sure you bring the right clothing, always check the weather before you go out. Always wear a life jacket, and tell someone your sailing plans. Never go to sea without a VHF radio.

Bring along useful gear like:

• Wicking base layers
• Good fleece midlayers
• Decent footwear with a grippy, non-marking sole
• A warm sleeping bag
• A head torch with a red lens (for night watches)
• A waterproof torch
• A mobile phone with a waterproof and shock proof case and charger brick
• Keep it all in a soft, waterproof bag/rucksack​

Step 7: Take a Sailing Course

One of the best ways to learn is by taking a class. Sailing schools teach:

• Boat handling under power and sail
• Learn to navigate
• Safety procedures and good practice
• Courtesy for other water users
• Rules of the road and bouyage
• Understanding weather and weather forecasts

Step 8: Keep Learning and Exploring

Once you know the basics, you can try:

• Sailing bigger boats
• Joining a sailing club
• Racing (competition always speeds up your learning)
• Cruising overnight
• Ocean crossings
• Working at sea on posh yachts!

Sailing is a lifelong skill. Every day on the water is a school day, so just get started! 

First Principles

First, it’s worth noting a few things. 

As seafarers, we are required by law to maintain a proper and effective watch using all means available to us. This means that as well as having at least one human on watch, we should use all other means necessary to aid that human. This might include radar, VHF, AIS, electronic and paper charts, the mk 1 eyeball and the enhancement of it through use of binoculars and even a powerful lamp. 

Many yacht deliveries operate on the basis of one skipper, one relatively experienced crew member and one other. I would consider this to be the minimum safe manning level, and it allows for the incapacitation of the skipper or second in command in a worst case scenario. However, this configuration means that only one person will be on deck at any one time whilst the other two crew are sleeping. 

As a general rule I always much prefer to have at least two people on deck at any one time. On larger yachts or when racing this might be three or more.

Second, it is important that the crew are sufficiently competent to stand watch without either constantly waking their colleagues or alternatively, not waking their colleagues early enough because they do not recognise potential dangers. This means that all crew standing watch must understand the IRPCS (or COL REGS) and also be able to either hold a course, trim sails, understand how to use the navigational aids on board and also be fully briefed by the skipper with regard to the skipper’s standing orders.

And third, it is useful to allow for unknown situations that might arise like illness, injury or sea sickness amongst the crew. As with everything else, the more redundancy you can build in the better, within reason.

Crew Selection

When selecting crew, the skipper will have several things to consider. Dependent on the nature of the voyage, the order of priority might change, so in no particular order, I list them as follows;

1. Personality Type & Character
2. Sex
3. Age & Health
4. Nationality, languages spoken & Visas
5. Fitness
6. Susceptibility to sea sickness
7. Transferable Skills
8. Personal dietary preferences & limitations
9. Sailing & navigational skills

Qualifications & References

Before most voyages there will be an element of preparation and this is a great opportunity to observe how your crew work together and perhaps even identify potential friction between crew or work-shy elements.

Bedding-In

It’s a good idea to have all the crew meet beforehand and participate in all the preparation whenever possible. It’s also useful for everyone to help with storing supplies and time spent here will save a lot of aggravation later as if only one or two people packed away the food, don’t be surprised if you are woken on every off watch by someone looking for the sweet Chilli Sauce!

If possible, maybe have a crew meal together a couple of days before you leave. Of course, this might be practical for an Ocean Crossing but not for a weekend sail to France and back.

Crew Jobs

Make sure everyone knows what is expected of them, where they may stow their own kit, where everything else on board is stowed and set out the rules and the jobs necessary for the running of the boat. On larger crews, I might have a rota for jobs like engineer, bosun, cook, cleaner, etc. This would change daily, probably on the breakfast watch change. In such circumstances, the new engineer, cook and cleaner would know to prepare breakfast, do engine checks and clean the heads before breakfast watch change. 

They would usually have a counterpart on the opposite watch ready to share those duties by perhaps washing up afterwards or doing generator checks before the evening meal.

On smaller boats the skipper might be engineer whilst the role of cleaner and cook rotates between the crew. Having a cleaner and cook on each watch is a good idea, if you want to eat on time and maintain clean heads and common areas.

I keep the jobs of cleaner and cook separate and I always keep the cleaner and the cleaning utensils out of the galley to avoid cross contamination.

Watch Systems

Most watch systems are based around meal times. This makes sense as the on-watch is too busy being on-watch and the off-watch want to rest. Therefore, except for very small crews, most larger watches revolve around breakfast, lunch and dinner. 

In a warm, temperate climate, especially during the day, a long watch is very manageable. However, night watches can drag and be very tiring, especially when it’s cold or wet. 

If you are on passage, boat time or local time might need to be adjusted by an hour every few days, as you sail either East or West. It’s worth remembering to make these time changes on alternate watches, otherwise, one watch will start to feel hard done by if they are always the ones losing an hour’s sleep!
​

​Most navigators navigate using UT and have a LT (Local Time) next to it in the log, for watches and possibly for other periodic duties such as engine and generator checks, cleaning, meal times, etc.

Option 1 (4-ON-4-OFF)

The simplest of all watches, this will have two watches rotating every 4 hours. The first day watch is usually breakfast at say 0600 HRS LT. Lunchtime will then be at 1200 hrs and an evening meal at say 2000 HRS. 

This is a simple system, but it has drawbacks. For a start, it only allows for short off watches, meaning crew have less than 4 hours to wash, eat and sleep. I say less than 4 hours because it’s usual for the oncoming watch to have eaten (if it’s a mealtime) and they should be on deck, appropriately dressed for the conditions, at least 10 minutes before watch change. This allows for a proper briefing of the new watch by the off going watch and allows for eyes to acclimate to the dark.

Meals are also no equally spaced throughout the day. 

Option 2 (6 - 6 - 4 - 4 - 4)

This watch system has several advantages over the 4 - ON - 4 - OFF system. For a start, it allows the off watch to sleep for longer at least once every 24 hours. This is particularly useful if you have had rough weather, as it allows crew to catch up with sleep. 

I usually have the long watches during the day when workload might be less and the temperatures are more comfortable. However, in the tropics, having the longer off-watches at night might be preferred by the crew as trying to sleep below deck in 36C+ during the day might be impossible. 

​If you allow everyone to snack, how do you know who is eating, who is not and what food you have consumed and/or have left?  

On larger crews, this sort of policy can become chaotic. I always have a roll call at every watch change. If you don’t do this, how do you know if you are all there? Especially if the watch is large, it’s dark and cold and everyone wants to get to their bunk?

Of course, these are just 4 options. There are many others. Personally, I feel options 1 and 2 are best, especially for larger crew. For very large crew (say 18 or more) it might be worth considering a 3 watch system. This allows for off watch crew to sleep for 8 hours at a time but it can mean that crew have to change bunks every watch. This is not always popular.

In an ideal world, the skipper will be outside of the watch system. This allows him to sleep when he doesn’t expect to be needed and to be available or on deck when conditions are more challenging. It also allows for him to rest after working for extended periods of time, due to poor weather or mechanical breakdown.

On commercial vessels, there is a legal requirement for the skipper and crew to monitor and log their hours of rest. 
​

Meals split nicely at 0600 HRS, 12 NOON and 1800 HRS.

Another great benefit of the 6 - 6 - 4 - 4 - 4 is that the watches are not symmetrical, meaning that each watch shares the extra watch on alternate nights and each watch gets to see the sun rise or fall every 48 hours. 

Option 3 (5 - 2 - 5 - 4 - 4 - 4)

A variation on Option 2, this has each watch doing a slightly longer off watch once a day but there is an overlap watch over lunchtime where both watch are up and active. This is great for keeping the watches socialised. It is amazing how tribal we are as creatures and it’s easy, especially if morale is low during or after heavy weather, for watches to build resentment over silly things. Having a couple of hours over lunchtime for watches to chart and socialise helps keep the boat happy.

Some skippers will actually call this period ‘happy hour’ and whilst each watch may or may not eat together, they will sit together on deck or below for a while. This is also a great time for the skipper to update the crew on progress and to issue new orders or notices. For example, the forward heads is blocked and I need a volunteer to fix it!’

It’s also a great time for the skipper to raise issues that might have been brought to him by other crew. This helps to nip in the bud simmering issues that might otherwise blow up into a near-mutiny later!

Option 4 (EASY-GOING/LAISSEZ-FARE)

Some skippers, especially with small crews, might be more relaxed about watches and allow crew to sleep when they are tired and make their own food. Whilst this can work, it’s worth noting a few serious drawbacks to this way of doing things.

Everyone, especially at the beginning of a voyage and during bad weather, will become tired and cold at the exact same time. Obviously, someone needs to stay on watch and whoever does will already be tired before they start! 

Eating as a group is a great way of building a cohesive team. It is a distinctly social human practice and you avoid it at your peril
​

​In this article we talk about weather forecasts and how to understand them

Sources of Weather Information
I'm only going to address inshore and coastal weather sources. I will talk about ocean-going weather sources provided via satellite or long range radio in another article. For the purposes of this article, I am talking about services available in the UK, but the principles around understanding a forecast are the same everywhere.
​

​The Boatie App, available in the UK, is simpler, but uniquely to these three apps, it does provide updates of the actual Met Office Shipping Forecast and Inshore Waters Forecast. 

In the UK, we also have other sources for weather forecasts, broadcast periodically in various forms. These include TV and radio (although only some radio stations provide sufficient detail for sailors). In particular, In particular, BBC Radio 4 broadcasts shipping forecasts on a regular basis at different times of the day.

Most marinas and harbours post weather for the coming +24 or +48 hours on their door or noticeboard. 

You can also gain access to periodic weather forecasts via your VHF. The UK Coastguard usually broadcasts announcements on CH16 and then broadcasts the current forecast on their designated working/weather channel/s. 

The best place to find broadcast information for different areas of the coastline is to look at your Reeds Almanac for the area in which you are sailing. The almanac contains a comprehensive table of coastguard stations, their broadcast times and forecast types and also details which channel they broadcast on for which area.

If you have Navtex, this can also provide you weather within about 250 miles of a coastal station and this option can be great for longer offshore or coastal passages.

Understanding a weather forecast
The first thing to appreciate is that a forecast is just that. It's not necessarily reality! Things can change. That said, modern weather forecasts in the northern hemisphere are usually fairly accurate up to +48 or even +72hrs ahead.

Be Ready
If you are listening to a forecast, detail is important. Most broadcasts are delivered at a reasonable pace, but sometimes they are rushed or radio reception can be poor, so make sure you are ready at your chart table with pencil and paper in hand and have no distractions. 

Know your Sea Area
If you are sailing in unfamiliar waters, make sure you know the boundaries of your sea area.  

Remember, whilst you are listening to a forecast on VHF, you may not be able to hear other traffic. Of course, you could set a dual watch on your VHF, but then it's likely you will miss parts of the forecast! Best let the deck monitor traffic via your handheld VHF and tell them to keep a good lookout.

Let's look at the +24 hour Inshore Forecast for the inshore sea area, Selsey Bill to Lyme Regis on Thursday 08 April 2021. There is then an outlook for the following day which I note as +48hrs.
​
​It is presented on Boatie as follows;

These numbers are referencing the Beaufort scale. If you want to see our video on how to convert Beaufort Scale to wind speed in knots, click here.

This means we can expect 5 - 10kts of true wind from the West. We can then expect it to back to the South West (which means move to the South West, anti-clockwise) and increase in speed to a F4 - F5 (approximately 15 - 20 kts). You might expect gusts of up to 25 - 28kts.

The wind will then decrease to F2 at times later (approx. 5kts).

SEA STATE: Smooth or Slight
As you'd expect from light airs at the beginning of the forecast, the sea state is forecast to be smooth, increasing to slight later, probably after the F4 arrives. A smooth sea state is 0.1 - 0.5 metres. Slight is 0.5 - 1.25 metre wave height.

WEATHER: Showers
Wear your jacket! It also suggests slightly unsettled weather. It could be gusty. 

VISIBILITY: Good
Good means visibility is more than 5 miles. On a small yacht, that's pretty much to the horizon in a flat sea. It also means no fog - which is always good!

That's great. We have a forecast and let's assume that it doesn't look like anything for our boat and our crew can't handle. What else can we get from this forecast?

Bringing Information Together

BAROMETER
Once on passage, we should be comparing our forecast with reality. To do this, we can monitor our barometer to measure and monitor changes in barometric pressure. If the barometer starts moving, we can expect a change in weather and if it is moving at speed, we know to expect more wind. Perhaps a lot more.

CLOUDS
Keep an eye on cloud cover. If high level cloud starts to cover more of the sky and/or cloud cover starts to thicken and come lower, you may have a depression coming your way. Check this evidence against the forecast. Turn your back to the wind and in the Northern Hemisphere, the centre of the low pressure should be to your left and slightly forward. This is called Buys Ballot's Law.

SEA STATE
Are the waves larger than expected? Is this because of the overfalls you are sailing through, the fast-flowing tide or is there a larger swell than expected? A large swell can suggest more wind is on the way.

Also, keep an eye out for rain showers and tall, isolated clouds that might suggest rain showers and localised squalls. In certain weather conditions, I've experienced 5 - 10kts of wind interspersed by violent squalls. It's quite common near the Doldrums or along the East Coast of Uruguay, for example, in October. 

In 2019, I spent an interesting 24 hours sailing along the coast of Uruguay in 10kt winds interspersed by huge 75 - 80kts squalls. That was sporty.

See below video of one of my competitors on that race, at that time, just a few miles behind us at the time.

​THE BIG PICTURE
And finally, we bring it all together. Remember that the wind is backing and increasing from the West to the South West. We have rain showers and wind is going to increase slightly. If we were to look at our isometric charts for the same period, we would see that the edge of a warm front passes just north of us, whilst we are on the very edge of a High Pressure system giving us light Westerlies. 

0 0 metres (0 ft) Calm (glassy)
1 0 to 0.1 metres (0.00 to 0.33 ft) Calm (rippled)
2 0.1 to 0.5 metres (3.9 in to 1 ft 7.7 in) Smooth (wavelets)
3 0.5 to 1.25 metres (1 ft 8 in to 4 ft 1 in) Slight
4 1.25 to 2.5 metres (4 ft 1 in to 8 ft 2 in) Moderate
5 2.5 to 4 metres (8 ft 2 in to 13 ft 1 in) Rough
6 4 to 6 metres (13 to 20 ft) Very rough
7 6 to 9 metres (20 to 30 ft) High
8 9 to 14 metres (30 to 46 ft) Very high
9 Over 14 metres (46 ft) Phenomenal

I hope this gives you a good indication of how to obtain and understand a weather forecast. Of course, you would update your forecast before you leave and whilst on passage and plan for alternate ports of refuge if the situation were to change.

Tidal patterns are not just influenced by the moon and the sun but also by the shape of the earth's surface. The more observant of you, especially those that live on South Island, New Zealand or the Scottish Highlands, will have noticed that the earth's surface is not uniform; it has variations in the shape of the continents, ocean basins, and underwater ridges.

These variations in the shape of the earth's surface can influence tidal patterns in specific areas. For instance, when the tide reaches a shallow area or a narrow strait, it can create a higher tidal range. Similarly, when the tide reaches a broad, shallow bay, it can create a lower tidal range.

Geographical features such as coastlines, estuaries, and bays also influence tidal patterns. In the same way, bays tend to create clockwise and anti-clockwise flows along the coast, as the tidal flow changes. 
​

Headlands, jutting out into a tidal stream may cause back eddies and violent overfalls, especially where the headland just into the stream by way of a shallower ridge, underwater. This forces the fast flowing water upwards at speed in order to flow over the shallower water.

The shape of the coastline can influence how high the tide gets, where it reaches its maximum, and how fast it recedes. For instance, in a concave coastline, the water is funnelled into a narrower area, sometimes creating higher tides. In contrast, in a convex coastline, the water is dispersed over a broader area, resulting in lower tides. Estuaries and bays act as amplifiers of tidal currents. The tide enters an estuary and gradually narrows, forcing the water to rise and creating a higher tidal range. 

In addition to the gravitational pull of the moon, sun, and the earth's shape, other factors can also influence tidal patterns. The wind is one of the significant factors that can influence the tidal flow. Strong winds can cause the water to pile up in one area, creating a temporary rise in the water level. This rise in water level is known as a wind tide. Additionally, when the air pressure is particularly high, or low, it can have a significant effect on the predicted tidal height at a specific location. 

It is not uncommon for coastal towns to experience floods when a particularly high equinoctial spring tide coincides with a strong onshore wind and an unusually low atmospheric pressure. In the South West of England, I regularly experienced this event in Salcombe, Devon.

If you'd like to know more about how to estimate tidal heights and flows for passage & pilotage planning and calculating an estimated position or course to steer, check out our multi media posts, below. If you want to know how to calculate tidal heights or flows check out our videos, here.