BC Ferries says sailings between Horseshoe Bay and the Sunshine Coast will be running at half capacity while the Langdale terminal undergoes major upgrades starting in January of 2017.
It says the main berth at Langdale will be closed from Jan. 19 to mid-April 2017.
However, the ferry service says it will be increasing the number of sailings to account for the reduced capacity.
"With twice as many sailings each day, the overall capacity will remain essentially the same," BC Ferries said in a news release.
During the closure, the Langdale-Horseshoe Bay ferry service will operate out of the secondary berth at Langdale terminal. That terminal only has capacity for single-deck vehicle loading, compared to double deck loading.
Once completed, BC Ferries said the upgrades would mean "at least 20 years of dependable service" from the main berth.
It is encouraging travellers to make reservations where possible.
The water taxi service to Gambier and Keats Islands will also be temporarily relocated from the Langdale terminal to the Gibsons Harbour Marina.
"These customers will be provided parking at the marina, as well as shuttle service between Langdale terminal and the marina to connect with certain sailings on the Langdale-Horseshoe Bay route," BC Ferries added.