Sailing Safely: Being Prepared and Weather Wise

Weather and where to look

Apr 8, 2024

For the leisure sailors and weekend warriors of Aotearoa and its picturesque coastal areas, the allure of the sea is undeniable. The promise of tranquil waters and the thrill of navigating the sea beckon many to embark on maritime adventures. However, the beauty of New Zealand's waters is matched by their unpredictability, making weather awareness not just a skill but an essential aspect of safe boating.

The Critical Importance of Weather Checks

Before setting out on the water, one of the most crucial steps is to check the weather conditions. The sea is a dynamic environment, highly sensitive to changes in weather. Conditions that seem benign at the start of your journey can quickly become treacherous, affecting not only the pleasure of your day but also its safety. Wind strength, rain, visibility and sea state are all influenced by the weather, and being caught unprepared can lead to unpleasant and dangerous situations.

Sources such as the weather channel on your VHF marine radio can provide vital updates for mariners, offering localised weather information that is crucial for planning a safe journey. Additionally, digital tools like the Coastguard App, Windy, and PredictWind have become indispensable for boaties, providing real-time forecasts, wind maps, and tide information. These resources allow sailors to make informed decisions about when to set sail and when to stay ashore.

Weather's Quicksilver Nature

New Zealand is known to have 4 seasons in one day and the maritime climate is no exception. A sunny morning can quickly give way to gusty winds and rain by afternoon. These changes are not merely inconveniences; they significantly impact boating conditions. Wind shifts can alter the course you need to steer to maintain your planned track, sudden rain can reduce visibility, and unexpected changes on the water can affect navigational plans. The chop, or small-scale waves created by wind, is particularly sensitive to weather changes. A sudden increase in wind speed can transform a smooth surface into a rough, challenging terrain for boats, especially smaller vessels. It is also important to note that tidal flow can have an affect sea state. When wind and tidal flow are in the same direction the sea state will be calm, but once the wind or tidal flow changes, so that the two forces oppose each other, the sea will become noticeably choppier.

This just highlights why it is so important to check the state of the weather on a regular basis throughout your day or weekend away. Weather patterns can change quickly and if you are a few hours away from a port you need to know what is happening on the water. 

One of the easiest signals of a weather change is the sky. Being perceptive and seeing the clouds shape change can indicate a change in weather.  There are four main types of cloud and they each give you an insight into the weather and any changes that may be coming your way.

Cumulus Clouds: Often likened to fluffy cotton balls floating leisurely across a blue canvas, cumulus clouds are the epitome of a sunny day's charm. These clouds are low-level formations, typically indicate fair weather. However, when they grow taller, they can evolve into cumulonimbus clouds, heralding localised thunderstorms.

Cirrus Clouds: High above the earth, cirrus clouds paint delicate strokes across the sky. These wispy, feather-like formations are composed entirely of ice crystals, reflecting the sunlight in breathtaking ways. Cirrus clouds are often seen as weather's artists, hinting at changes in the air currents and signalling a change in the weather.

Stratus Clouds: The overcast skies that bring grey days are often the work of stratus clouds. These low, uniform layers cover the sky like a blanket, sometimes bringing light mist or drizzle. Stratus clouds might not boast the drama of towering thunderheads or the ethereal beauty of cirrus formations, but their presence is a familiar part of the landscape, especially in cooler, damp climates.

Nimbus Clouds: Bearing the Latin name for "rain," nimbus clouds are the bearers of precipitation. Whether in the form of rain, snow, or sleet, these clouds are dense and dark, loaded with moisture ready to be released onto the earth below. Cumulonimbus and nimbostratus, subcategories of nimbus clouds, are particularly associated with heavier weather phenomena, including thunderstorms and continuous rain showers.

Understanding weather dynamics is crucial for navigating safely. Always make sure you have a passage plan with a few options of where you might be able to anchor if the weather changes even if you are just going out for a day.

Seasonal Weather Variations and Hypothermia Risks

Transitioning from summer to winter also brings a host of changes to New Zealand's coastal weather patterns. Cooler temperatures, increased precipitation, and stronger winds are common, affecting sea temperatures and overall boating conditions. For leisure sailors, understanding these seasonal shifts is essential for proper preparation.

One of the most significant risks associated with colder weather is hypothermia. Immersion in cold water can rapidly draw heat away from the body, leading to a dangerous drop in core temperature. This risk underscores the importance of having the right gear onboard and knowing what the sea temperatures are as part of your weather assessment before heading out. Wearing appropriate thermal protection and having emergency gear onboard can make a critical difference in safety.


For those who love to get out on the water, weather awareness is the cornerstone of safe and enjoyable boating. By utilising reliable weather information sources and understanding the profound impact of weather on sea conditions, boaties can navigate with confidence. Remember, the sea's mood is reflective of the sky above; so keep an eye on this and always check a reliable weather source!
Sailing Safely: Being Prepared and Weather Wise

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