We stayed in Picton (the top of the South Island) recently. We booked an online bach which featured fantastic views out of the lounge window. We enjoyed this view several times a day when a Cook Strait Ferry journeyed its way from Picton to Wellingon or vice versa.
There were many fishing and leisure boats travelling back and forth as well. Together they created a panoramic picture out our window where we could sit and enjoy it all.