Now that Oso has arrived in New Zealand, successfully navigated the very strict entry protocols to have the boat accepted into the country, and enjoyed a local pint or two overlooking the pastoral beauty of Northland’s Bay of Islands, it’s time for a summary and some reflections of our passage south from Tonga.
- Total distance: 1144 nm
- Total time: 6 days, 6 hours
- Average speed: 7.6 kts
- Motoring time: 36 hours (Ugh!)
- Number of whales seen: 0
- Number of dolphins seen: 0
- Number of other boats seen: 1
The passage to New Zealand from the tropics has a reputation as a challenging one, largely because of the sometimes strong and often rapidly changing weather conditions upon arrival. New Zealand sits partly in the latitude of the variables and partly in the latitude of the westerlies, with the mighty Southern Ocean between the islands and Antarctica. Strong low pressure systems generated in the Southern Ocean roar up the Tasman Sea between NZ and Australia, and then sometimes continue northeastward, sometimes peter out, and sometimes sit for awhile over NZ, churning up the seas in the area. These systems are typically fast moving and tend to be more challenging to forecast than weather in other parts of the world.
When we left Tonga, we had a fairly decent weather forecast – it looked like good sailing across the tradewinds for the first four days, maybe a half day of motoring through a high pressure area, and then fast reaching in moderate southeast winds as we arrived in NZ. But the passage would take about 6 days, and our experience with weather forecasts is that starting around day five, the forecast accuracy falls precipitously.
So as we sailed southward, we kept a close eye on the weather. And sure enough, the forecast started to change. Most frustratingly, the stretch we would have to motor extended, but we also started to note unsettled conditions forecasted to develop as we approached NZ. The predicted strength of the wind would vary as the forecasts updated over time, but the strongest wind in the forecast was 25-30kts – not even a gale. Those winds, which typically generate ~10’/3m seas or so, are conditions we’d sailed through multiple times, both in Oso and in Madrone. We changed course slightly so that we could take the stronger winds at the best angle for the boat, and then pressed on towards New Zealand.
Sure enough, the wind began to increase the morning of our final day of sailing, and with the forecast suggesting it would build rapidly we set a conservative sail plan – 3 reefs in the main and just our staysail ahead of that. Within 20 minutes, the wind was blowing steadily in the mid-30s, with gusts near 40kts. Even though the wind was quite a bit stronger than forecasted, those are also conditions we’ve sailed through multiple times, so we took note but weren’t particularly worried.
Within about a half hour of the wind starting, however, the waves built in a way that we hadn’t seen before. Relatively speaking, the waves weren’t that high – perhaps 13-16’/4-5m – definitely large but pretty normal for winds in the 30kt range. But the faces were amazingly steep, and the period was very, very short, with another wave arriving only 6 or 7 seconds after its previous neighbor.
It was a sea state we had never seen before, even as a part of much larger storms with much stronger winds that we’ve sailed through. Conditions were very rough and quite uncomfortable – easily the worst sea conditions we’d ever been in.
It wasn’t really that windy, relatively speaking, and there really wasn’t much background swell. So what caused the terrible conditions? Wind blowing against a current produces especially steep, short period, disorganized waves, and this is the only thing we can imagine that could cause such a sea state in those wind conditions – a strong current flowing towards the south, directly into the wind coming from the southeast.
We were lucky that these conditions only lasted about 4 hours or so, and when we arrived at the customs dock in Opua we were a bit shaken and feeling that perhaps our sailing skills weren’t quite as salty as we sometimes imagine them to be. But there were a pair of local NZ boats that had also just arrived – the crews of each of the boats told us they have been sailing these waters for more than 30 years and had never experienced conditions like the ones we had all just sailed through.
As we began to clean up the boat, our VHF radio crackled with a call from a boat just a couple of hours behind us – they radioed the NZ coast guard to request assistance if conditions deteriorated further. And a few minutes later, we heard a second call – a 62′ sailboat, even larger than Oso, had just lost their mast overboard. So it was not our imagination – conditions were very, very poor.
After a night’s sleep, we of course discussed what had happened, how we handled it, and what we could do better in the future. We agreed that perhaps a little bit less mainsail could potentially have helped, although there are also reasons that could have been a negative. And we agreed that with a similar weather forecast in the future, it’s hard to imagine that we would decide to alter course, or to stop the boat and wait for better weather. If we avoided every area of slightly bad weather, we’d never get anywhere!
In the end, we decided that two things were simultaneously true: First, we had just been very unlucky to be in the wrong spot at the wrong time, and second, we had been very lucky to come through physically unscathed and just a bit mentally scarred.
We’re even happier than normal to make landfall!
