The membership, which includes about 250 workers, voted by a margin of just over 70 per cent to accept the deal.
The Newfoundland and Labrador Association of Public and Private Employees says the workers rejected an offer brought to them last October because of operational issues such as scheduling, but it says those items have been addressed during a conciliation process.
The agreement includes an increase to the overtime allowance from about $2,700 to almost $4,300 annually.
It also allows new scheduling flexibility so the Department of Transportation and Works can change the sailing schedule twice a year without incurring additional costs.
The government says that will allow the department to work with communities to better meet seasonal transportation needs.