A beginner’s guide to Lyttelton Harbour’s sailing conditions
(updated November 2011)

(above - March 2010. A southerly front forms over the Wednesday night racing in Lyttelton Harbour. 52 knots with hail. It lasted for just 15 minutes. Its NOT normally like this!!Thank you to the Naval Point Facebook Page)

Our fantastic harbour can provide you with a sunny scenic day out with lots of activity and interesting sights to see, however it can also give you a day out sailing with the family that you will NOT want to remember, especially if you don’t understand its weather systems.  
            Nor’easter (55%) (cool, steady and often sunny)– It’s the most common wind we get,  (prevailing) comes straight down the harbour. Typically it builds up from 5 knots to a peak between 1pm & 3pm of 12 - 18 knots then eases off again as the day’s temperature dies down. Be careful in the region in front of Quail Island; the wind is about 10 knots stronger here than at the heads and develops a short choppy swell of up to 1.5 Metres.  Winter Easterlies can be quite light and very pleasant; the club jetty is excellent in these conditions.  Good Point sailing in Easterly conditions in the harbour.
            Nor’Wester (25%) (very warm, savage & sunny, known also as a Foehn Wind). This looks ideal but beware: the winds gust up to 40+ knots in the harbour and can knock you flat. The warmer the air the stronger the gusts! The Nor’ west winds seem to funnel near the Corsair bay area and will affect Diamond Harbour moorings Purau and Little Port Cooper. The club jetty can prove difficult in stronger winds with the boat being pinned to the floater, so don’t be afraid to ask for a little help to get back on your trailer. What do the clouds look like? check here,  The classic Norwest Arch
           Southerly (20%) (cold, dangerous and cloudy) – One good way of putting the family off sailing is to be out on the water when a Southerly hits the harbour! Southerly winds can be a few hours later or earlier than predicted. They typically have a ‘front’ which covers the harbour very rapidly with high winds, easing off once the initial front has passed. The rest of the Southerly system may settle in for a few days so have a look at ‘where to run’ below.  Signs of a Southerly front approaching include a rapid build up of cloud on the hills above Diamond Harbour and a drop in temperature.  If in doubt – don’t go out!

Where to run in a Southerly.

The club slipway may become dangerous since it has limited protection in Southerly winds, especially if above 18 kts. If you have a trailer yacht then we suggest you motor into Lyttelton Harbour, HARD LEFT TURN, and use the public slipway next to Starks to retrieve your boat. Remember to lower the mast if moving it back to the compound (low pipes across road). Diamond harbour, Quail Island (North side) and Purau are good places to seek shelter while you prepare to sail back in the new conditions. Don’t attempt to tie up to the old marina; the Southerly swells can get very high there as it is totally unprotected. If you get stuck with your yacht bouncing around at the club jetty, don’t be afraid to ask for help and advice, we’ve seen it all before and know what to do!  The public slipway near Naval Point is also dangerous

Here is a Lyttelton Forecast showing how variable the harbour can be:

Outlook: Thursday:Variable 10 knots becoming northeast in the afternoon. Cloud clearing.
                Friday: Northwest 10 knots, rising late Friday southwest 25 knots with showers.
                Saturday: Southwest rising to 30 knots early, easing to 10 knots later. Showers clearing later

So from this we can see Thursday is ideal, Friday you may get a bit of sailing in the morning but be prepared, the Southerly may be early, and get ready for a 30 knot front if it says 25 knots, keep an eye on the hills for cloud formation & plan for a fast exit! Saturday, only the brave and foolish go out! But you could get in some damp sailing in the afternoon on the dying Southerly with caution. ( Actually rather nice!)
www.metservice.co.nz – marine – recreational – Christchurch .      
Dudley Jackson - www.learn2sail.co.nz

Please ask before re-producing this document, thank you

Note. The Southerly winds produce some pretty serious storms. The Lyttelton Marina was compleatly destroyed during October 2000, they are nicknamed 'old man southerly'. The Metservice has written an interesting artical on this