We booked return on the ferry for our holiday and we were pretty impressed going over(in spite of swell maps on google looking pretty bad) and the strait was pretty flat.
Coming back today was windier but the captain and boat performed very well. Imagine our horror though when we realized that they had left our luggage in the bin on the island. We put it where we were told so it was definitely their fault. Lucky for them we were stopping in Invercargill over night so it caught up with us5 hours later!