New Zealand's weather can be highly unpredictable. Enjoying the sunshine and a light breeze at home is one thing, but the wind can be twice as strong out on the water.
We've got you sorted with a range of services to keep you on top of what the weather is doing.
How to get the latest forecasts
Never expect the sea state to stay the same as when you set out. Marine weather forecasts tell you what the weather is expected to do, but there’s no guarantee it won't get worse. Keep an eye out for unforecasted changes of clouds, wind direction and strength.
The new generation Coastguard App features 5 day forecasts, the real-time weather situation and the ability to make a trip report right from your smartphone. It's got a boatload of handy features for fishos and boaties, you won't want to leave the dock without this game changer in your pocket. Check out the new Coastguard app.
Coastguard VHF Radio
Live weather Broadcasts are broadcast four times daily via Coastguard Radio and cover recreational forecasts, sea areas, tides, navigation warnings and local station notices. Wind warnings are broadcast as soon as they're issued, and every two hours until they are cancelled.
Coastguard Nowcasting (VHF Radio)
Coastguard's Nowcasting service broadcasts real-time marine weather information and forecasts. It's available continuously via your marine VHF radio or the Coastguard app.
Check out the VHF and Nowcasting channel maps here to find your local channel.
What to look out for
Here's the information contained within a typical forecast and weather situation, and what you should look out for.
- Wind direction, such as north-west, is the direction the wind is coming from. Wind speed is measured in knots (where 1 knot is about 2km/hr)
- Wind gusts can be as much as 50% stronger than forecast wind speeds. The terrain nearby (such as close headlands) can cause a funnelling effect, further increasing wind speed - something to watch for.
- Forecast wind speeds are ranges, not exact. Average wind strengths are described in 5-knot increments. A given wind speed implies a 10-knot range. For example, with a forecasted wind speed of 15 knots, you should expect average wind speeds between 10 to 20 knots.
- Wind direction is stated in the “true” compass direction (such as north and south) from which the wind will come, versus magnetic.
- Tides are important. When there's wind against the tide, the sea will be much rougher (especially for those aboard boats under 6m in length).
- Swells are caused by longer waves coming from the ocean, which increase in height and intensity as they approach shallower water.
This is included in the forecast when it's expected that visibility is going to be less than 6 miles (10km).
All marine forecasts are for up to 48 hours, and usually also contain the outlook for the following 3 days.
Wind warnings are issued for coastal gales, storms or squalls, with strong wind advisories issued if the wind is set to exceed 25 knots.
Crossing a bar
Never cross a harbour or river bar without the required experience and local knowledge.
When you go to cross a harbour or river bars, it's vital that you understand the action of weather and tides.
- Check the weather within 12 hours of heading out, and keep an eye on the forecast for when you're due back.
- Watch the wind - if it's against the waves, the sea state will be much rougher.
- Avoid crossing at low tide when the action of a bar is amplified.
- Avoid crossing at ebb or falling tides, which is when water flows away from the shore
- Always make a bar crossing report to Coastguard - we'll put you on a watch, so if you can't call back in we'll initiate a search.
Never cross a bar without the required experience and local knowledge, so you know that conditions will be safe both on the way out and when it's time to head home. Read more about crossing a bar safely.
Know your limits and stay within them. If in doubt, don’t go out.
Boatie's Best Mate.
Get a Coastguard membership today for peace of mind when you’re out boating.