Is the Bay of Islands rough? What to expect on the crossing
Sometimes, and mostly at the outer end. The bay is a drowned valley with 144 islands, but the Hole in the Rock cruises run out to Cape Brett, which reaches into the open Pacific. Explore Group says it goes through the hole only when sea conditions allow.
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Bay ยท Northland, New Zealand ยท Reputation among passengers: mixed: commonly reported as uncomfortable in the wrong conditions.
- Low
- Moderate
- High
- Very high
Roughness summarises typical reported conditions for this crossing, not a forecast for any given sailing.
Open Pacific at Cape Brett, islands inside
In the Nausea Index table of the 121 sea crossings we cover, the Bay of Islands is rated manageable, one of 81 in that band, with 40 rated higher. Full table: the roughest sea crossings, ranked.
Key facts
- The Bay of Islands is a bay, and passenger reports place it in the moderate roughness band.
- The mechanism behind that reputation: Open Pacific at Cape Brett, islands inside.
- Conditions are reported roughest in May, June, July and August.
- The calmest months are usually October, November and December.
- It is also known as Te Pฤwhairangi.
Why does the Bay of Islands get rough?
The bay itself is a 16 km wide drowned valley system and natural harbour with 144 islands. Cape Brett, at its eastern end, extends north into the Pacific Ocean, and the Hole in the Rock on Piercy Island lies about 500 metres off the cape. Winds in Northland are mostly from the southwest, and it can be very windy in exposed areas. Gales occasionally arrive with depressions of tropical origin.
When is the Bay of Islands roughest?
Winds in Northland are mostly from the southwest. Stormy conditions from former tropical cyclones occasionally arrive in summer. Modelled wave heights for the open water off Cape Brett peak from May to August, with July the highest, and are lowest from October to December.
| Roughest water in Jan | Roughest water in Feb | Roughest water in Mar | Roughest water in Apr | Roughest water in May | Roughest water in Jun | Roughest water in Jul | Roughest water in Aug | Roughest water in Sep | Roughest water in Oct | Roughest water in Nov | Roughest water in Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Mixed | Mixed | Mixed | Mixed | Rough | Rough | Rough | Rough | Mixed | Calm | Calm | Calm |
Typical seasonal pattern, not a forecast. Any month can deliver a calm crossing or a bad one. Check the marine forecast for your sailing date. Select a month to see every sea and ferry crossing ranked for it.
Where to be on board
Front to back
- Bow (front)Avoid
- MidshipBest
- Stern (aft)OK
The crossing: 40 minutes to 5.5 hours
Roughest stretch: The run out to Cape Brett and the Hole in the Rock
Sit low and near the middle for the run out to Cape Brett, where the boat leaves the islands and meets the open Pacific.
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The crossings that cross it
| Route | Typical duration | What to know |
|---|---|---|
| Paihia or Russell, Hole in the Rock cruise (Discover the Bay) | 4.5 hours | Explore Group cruise with a 1.5-hour stop at Otehei Bay. It goes through the hole when sea conditions allow. |
| Paihia, Ocean Adventure to Cape Brett and the Hole in the Rock | 1.5 hours | Explore Group fast boat, September to April. The 1-hour Ocean Blast stays in the inner bay. |
| Paihia or Russell to Otehei Bay, Urupukapuka Island | About 40 minutes each way | Explore Group ferry among the islands. |
| Paihia or Russell, Dolphin Eco Cruise | 5.5 hours | Explore Group wildlife cruise, operating October to April, with a 1.5-hour stop at Otehei Bay. |
What helps on this crossing
- The open-sea part is the run out to Cape Brett. Stay low and near the middle of the boat there, and keep your eyes on the horizon.
- The Discover the Bay vessel has large viewing decks and an air-conditioned cabin. Use the deck for the cape run, where the horizon is in view.
- Ask Explore Group about conditions on the day. It says every departure depends on sea and weather conditions, and it may change a route or cancel for passenger safety and comfort.
For the full toolkit see the seasickness guide, or what to do once it has already started. For what the trials actually say about the oldest trick on that list, see the verdict on looking at the horizon. If the rocking follows you ashore afterwards, that is land sickness, which is normal, and it passes.
Frequently asked questions
Is the Bay of Islands rough in July?
July is the roughest month in modelled data for the open water off Cape Brett, where the daily peak wave height averages about 2.1 m. That is the open Pacific end of the Hole in the Rock cruise, not the inner bay among the islands. Explore Group can change a route or cancel a departure for passenger safety and comfort.
Is the Bay of Islands rough in January?
January is a moderate month in the same modelled data, with the daily peak wave height off Cape Brett averaging about 1.7 m. Summer is also when stormy conditions from former tropical cyclones can occasionally arrive. Check the forecast for the day of your cruise.
Does the Hole in the Rock cruise always go through the hole?
No. Explore Group says it travels through the hole when sea conditions allow. Wikipedia says boats go right through if the waters are calm and the tide is right.
Which part of the Bay of Islands cruise is roughest?
The run out to Cape Brett, which extends north into the Pacific Ocean at the eastern end of the bay. The Hole in the Rock lies about 500 metres off the cape. The ferry to Otehei Bay crosses among the islands to Urupukapuka, the largest island in the bay.
Other crossings
Sources & further reading
- https://www.exploregroup.co.nz/bay-of-islands/discover-the-bay/
- https://www.exploregroup.co.nz/bay-of-islands/ocean-adventure/
- https://www.exploregroup.co.nz/bay-of-islands/dolphin-eco-cruise/
- https://www.exploregroup.co.nz/otehei-bay/otehei-bay-ferry/
- https://www.exploregroup.co.nz/general-terms-conditions/
- https://en.wikipedia.org/wiki/Bay_of_Islands
- https://en.wikipedia.org/wiki/Cape_Brett
- https://en.wikipedia.org/wiki/Hole_in_the_Rock_(New_Zealand)
- https://en.wikipedia.org/wiki/Northland_Region
- https://niwa.co.nz/climate-and-weather/regional-climatologies/northland
- https://open-meteo.com/en/docs/marine-weather-api
Sea conditions described here are typical patterns drawn from published marine and operator information as of July 2026, not a forecast: conditions on any given sailing depend on the weather that day, and any month can deliver a calm crossing or a bad one. Route and operator names are trademarks of their respective owners; Dizzout is not affiliated with or endorsed by them. Seasickness sensitivity varies from person to person; this page is informational and not medical advice.