Queen Charlotte Sound tides, weather and the best months

Queen Charlotte Sound is sheltered, and that shapes everything. The main cruise operator says its boats sail in wind and rain and that cancellations for extreme weather are extremely rare, the sounds being sheltered water.¹⁹ It also rates seasickness as very unlikely on the sound, which is narrow and not very deep.²⁰ If you are nervous about boats, a cruise inside the sound is a gentle way in.

Cook Strait is different. Interislander explains that the strait makes up a third of its crossing and reacts to wind direction as much as wind strength.²¹ Southerly winds can bring long rolling swells from the Southern Ocean, while northerlies usually raise short, steep waves that big ferries cut through.^22,23 When conditions exceed the ships' limits, sailings may be delayed or cancelled.²⁴

The council runs weather stations around Queen Charlotte Sound that give real-time readings for safe navigation, and it publishes wave and swell information for Cook Strait and the northern entrance to the sound.^25,26 If you are skippering a hired boat or paddling a kayak, look at those readings and the marine forecast before you go. Plan longer crossings early in the day, when you have the most time to wait out a change.

Queen Charlotte Sound water temperature is not posted with the council's live harbour data, which concentrate on wind, swell and current for navigation.^25,26 In practice the season tells you most of what you need. Test the water at the beach before committing to a long swim, bring a wetsuit if you feel the cold, and remember that a calm surface says nothing about the temperature below it.

The council marks swimming areas with yellow buoys and keeps them for swimmers from Labour Weekend to Easter.⁷ You will find them at the Picton Foreshore, Shelley Beach and Waikawa Bay, and on the far side of the region at the Havelock Channel.³⁵ Outside those zones, remember that boats share the water, and the limit of 5 knots within 200m of shore protects swimmers as well as divers.³⁶

Warm, long summer days also bring toxic algae, which the council says are particularly prolific in that season.³⁷ Check notices at the beach and keep dogs out of water that looks scummy or discoloured. On a boat, everyone must carry a lifejacket in Marlborough waters, and anyone aboard a vessel no longer than 6m has to wear one.^38,39 A cold sea is far less forgiving than the calm surface suggests, so wear the lifejacket rather than stowing it.

Daylight swings widely through the year. The NOAA records behind the chart on this page give roughly 15.1 hours of daylight around mid-December and roughly 9.2 hours around mid-June.^5,5 Long summer evenings let you squeeze a late cruise or swim into the day, while in winter the light goes early. The sun chart on this page plots sunset month by month on New Zealand time, summer time included.

Afternoon departures are common on the sound. Mail boat departures from Picton are at 1:30 PM on its seasonal days, and the return time depends on the route and the amount of mail.^16,45 In midwinter that means a return in fading light, so pack a warm layer. In summer the same trip ends with hours of daylight to spare for a meal on the waterfront, and the return runs later in the warmer months.⁴⁵

A few seasonal hazards are worth a note. Wasps are common in late summer and autumn, especially on beech trees, so carry antihistamine if stings affect you.²⁸ The Sounds keep a restricted fire season all year and any fire needs a permit, and DOC may close the track in extreme drought and fire risk.^46,47 These are small hazards that a little planning handles: a light pack of essentials and a look at the forecast.