Weather or Not: Staying Safe in Unpredictable Conditions

Author: Will Hay

Spring always marks the start of the traditional boating calendar, usually with Labour Weekend as the unofficial kick off for boating across the country. As a transitional season it’s characterized by rapidly changing weather patterns, so it’s not uncommon to experience a mix of bright sunshine, strong gusty winds, and sudden rain showers all within a few hours. These unpredictable conditions are caused by the interaction between warm and cool air masses, which frequently clash, creating unstable weather.

In coastal regions, these variations can be even more dramatic. The land heats up faster than the ocean, which can cause strong onshore winds during the day, while cooler evening temperatures can create calm or foggy conditions. Understanding this dynamic is crucial for any boatie, especially if you're planning longer trips or venturing into open waters.

Marine Weather Forecasts: Your First Line of Defence

The key to safe boating during any time but especially in spring is knowing how to read and interpret marine weather forecasts. These forecasts offer detailed information about wind speed, wave height, and the possibility of storms or rough seas, which are essential to planning a safe trip. Check these regularly, not just before your trip as the shoulder season’s weather can change rapidly due to one or a combination of elements as described below:

• Wind: Spring winds can shift quickly, especially in coastal areas where most boating happens across NZ. Keep an eye on forecasted wind speeds and directions, gusts over 15 knots can make boating challenging especially for smaller vessels. Pay attention to the direction as this can alter your plans of where to head out, while anything above 20-25 knots may require reconsidering your trip altogether. The old saying of ‘If in doubt, don’t go out’ is crucial to heed, especially if you haven’t experienced wind conditions forecasted. A 5-knot difference doesn’t sound like a lot in terms of speed but it can have a magnitudinal effect on the sea state.
• Waves and Swell: High swells can make for a rough ride, and springtime can bring swells from multiple directions. Swells are caused either by wind as mentioned previously, or due to offshore weather creating groundswells which travel long and far to reach our shores. With nothing to interrupt them on the journey, NZ can often be exposed to large seas. Pay attention to forecasts that include wave height and period (time between waves) which will give a clearer picture of sea conditions. A shorter period between waves often signals rougher waters, usually caused by windier weather. Swell forecasts should always be read in conjunction with wind direction and tides as the conditions may be nice and calm when the swell, wind, and tides align, but when you get one of multiples acting against each other, things can rough up quickly especially around change of tide. Many seasoned boatie will have a story about an ill-fated ‘wind against tide’ experience which made their boating at best unpleasant and at worst catastrophic.
  
  
• Barometric Pressure: Monitoring barometric pressure is a good longer-range indicator that can help predict when storms may approach or what the general weather state should be. Barometers measure air pressure at a certain period and location so it’s important to note the changes around this and how they affect weather. In a high pressure state the air presses closer to the Earth’s surface, where the temperature is warmer, and the air can sustain higher levels of water vapor levels—resulting in a warmer, clearer day. In a low-pressure system, the air congregates higher up in the atmosphere, where the temperature is cooler and less capable of holding water vapor—resulting in a cold-weather day with a higher chance of precipitation.  Thus, higher pressure is indicative of calm weather, while low barometric pressure indicates poor weather. However as indicated before its vital to look at the changes and where the pressure is in relation to a map/geography as winds blow away from high pressure so it’s a good indicator of where the wind is going. The closer the isobars (those wavy lines in between high- and low-pressure zones) means a greater/faster change in pressure and therefore wind.

Fortunately, in this tech heavy day in age you can access instant weather information at the tap of a finger. To stay on top of the latest conditions, use resources like your local VHF weather nowcasting channel, marine weather apps like Coastguard, Predictwind, Metservice, and your local weather websites. Do not rely on overseas websites as the information can often be generic (ie blanketed across the whole country) and are usually not up to date. Make it a habit to check the forecast not only before you head out but also during your trip, especially if you're going far from shore.

Know the Signs: Recognizing Changing Conditions on the Water

Even with the best preparation, spring weather can be unpredictable as highlighted. That’s why it's important to recognize some key signs of changing conditions while you're on the water.

• Darkening Skies: A clear sign that rain or storms may be approaching. In coastal areas, storm systems can move quickly, so if you notice dark clouds gathering on the horizon, it may be time to head back to shore. While rain may not sound like much of a drama, (you’re on the water already, what’s a bit more right..) it can quickly reduce your visibility especially when underway so it’s crucial you respect the elements and adjust your trip or speed accordingly.
  
  
• Shifting Winds: A sudden shift in wind direction or an increase in wind speed often signals a change in the weather. Pay attention to gusts and be prepared to adjust course, reduce speed or call it a day and head home. As with the rain, watch the clouds and check how quickly they are moving across the sky. While you may be sheltered at surface level, wind only a couple km up can be a lot different and during Spring especially these winds can move about up and down through the air column fast with changing temps making what was a pleasant day suddenly windy.
  
  
• Dropping Temperatures: Linking to above, a sharp drop in temperature can indicate an incoming cold front, which may bring rough seas or stormy conditions. Keep an eye on your temps especially in the afternoons as this can cause sea breezes to gust up as this air shifts around you.

When you observe any of these signs it’s crucial to take proactive steps, if you’re close to shore, consider heading back early. If you’re further out, reduce speed, secure loose items, and ensure all passengers are wearing lifejackets if not already.

Adapting to Spring Conditions: Practical Tips for Safer Boating

Even though spring is a season marked with unpredictable weather there is usually still good boating to be had. That said it’s important to keep a few things in mind before and during your trip out on the blue to ensure the safety of yourself and your crew

1. Have a Backup Plan: If the forecast looks questionable, have an alternative route or a backup day for your trip. Labour Weekend may seem ideal for boating given the extra day off work, but if conditions are unfavourable, it's better to reschedule than take unnecessary risks no matter how itchy you are to get the hull wet.
   
   
2. Shorten Your Trips: In spring, it’s a good idea to keep your boating trips shorter and closer to shore. If the weather changes, you’ll be in a better position to reach safety quickly.
   
   
3. Monitor Conditions Constantly: Don’t rely on the morning forecast to get you through the day. Use your VHF, apps, or onboard systems to monitor real-time changes, especially during longer excursions or overnighters.
   
   
4. Know When to Turn Back: If conditions start to worsen, don’t push through. The ‘she’ll be right’ attitude can be dangerous when it comes to boating. If you notice the seas getting rougher or the wind picking up, it’s time to head for safety.
   
   
5. If caught out: Despite your best efforts, you might find yourself in a difficult sea state. If so, slow down as reduced speed will help maintain your control, and change course adjusting for swells and chop to keep the boat as steady as you can. Stabilise your boat by stowing loose gear and get your crew to sit low and in the middle of the hull to further improve stability and safety, especially in smaller boats.

And lastly if you are in danger call for help. Don’t risk a fatal event as your pride got in the way to radio CH16. Coastguard is always ready to assist you in getting home safely but they need to know you are there firstly.

Although spring has yielded many a trophy fish of their lifetime, the unpredictable nature of its weather can catch you out quickly. Coastal areas may experience strong fluctuating winds during this changing season, so be sure to check your local forecasts before heading out.

Fishing in the lee of the wind, protected by an island or headland may give a false sense of security so make sure when you’re out on the water, you still pay attention to the conditions & forecast so you don’t get caught out on the return journey. While daytime temperatures are pleasant, Spring evenings and early mornings can still be winter chilly, so gear up accordingly, especially for those change of light sessions.