Here's the sea on the Cook Strait ferry crossing on our recent trip down to Dunedin. We had to wait an extra day before it was calm enough (!) As an artist, I loved the texture. As someone with a stomach, I found it best outside in the wind.
The winds funnel through the strait, and this, combined with rips and cross-rips, make this one of the world's roughest three hours of water crossed daily. Actually, the worst bit is only about three-quarters of an hour. But that can seem a looooong time when all around you people are using paper bags. Not on this trip, thank goodness, although there were some sad faces.
As soon as we were inside the Marlborough Sounds, the sea calmed down. What a difference!
Here is a clip from another crossing. Lots of bag use on this one, I'd say.