Some Lyttelton residents were disturbed by the engine noise from huge dredging vessel the Fairway last week.
Taking to Lyttelton community Facebook pages, some said it was a nice reminder of what living in a port town was all about.
Others wanted to know if the rumbling engine noises were keeping others up at night as well.
The Lyttelton Port Company said it understood the Fairway was louder than most other vessels in port, and had been heard by several residents last Monday night.
The port company said the Fairway’s engines made a distinctive low frequency noise.
“We apologise for any disruption this has caused and appreciate your patience,” the statement said.
While in port, the Fairway was running on the minimum possible power, but engine noises had not reduced significantly.
The Fairway was in port for two nights and began dredging operations at first light last Wednesday.