It's still unknown exactly what caused the MV Salish to run aground at the Coupeville ferry terminal Sunday afternoon.

State Ferries spokesperson Ian Sterling says Keystone Harbor is the most challenging landing in the system with "zero room" for something to go wrong.

Ferry service for the Port Townsend/Coupeville route was halted for several hours after the "soft grounding" of the Salish. Soft grounding means the vessel was freed without assistance.

"A lot of people rely on the ferry to get on and off the island," said witness Jeff Arbuckle. "I could tell from all the cars down here there were a lot of people stuck and a lot of people who couldn't make it to the island."

Wait times out of Coupeville on Monday reached three hours. A ferry spokesman said repairs to the 748-passenger ferry will likely take days but not weeks.

WSF advised drivers to take the Edmonds/Kingston and Mukilteo/Clinton ferries as alternate routes. WSF also advised using Seattle/Bainbridge or Seattle/Bremerton as alternate routes.

Nobody was injured went the vessel during the incident.

Video taken by witness Tom Bajema shows the ferry pulling back and forth multiple times in an attempt to dock.

The vessel's rudder is currently stuck. It's unclear if that contributed to the grounding or if the rudder became stuck because of it.

Sterling says the goal is to get divers in the water or the boat lifted to determine what repairs are need. The goal is to get it back in service as soon as possible.

Meanwhile, the Port Townsend/Coupeville route will be on one-boat service. That is standard during the winter sailing schedule, which goes into effect in January.

Check ferry alerts and ferry/vessel watch times on the Washington State Ferries website.