Pressure could be even greater as a series of Highway 99 closes through Seattle begin at about the same time.
Ferry officials say there will be increased staff at the Seattle, Bremerton and Bainbridge terminals to accommodate larger crowds.
An extra sailing has been added to the Seattle-Bremerton run (10:15pm out of Bremerton and 11:30pm out of Seattle).
Officials say they will keep terminal supervisors on duty until the game is over and crowds thin. Terminal managers will also be present at all terminals.
WSF says it is adding more detailed travel alerts, more visual pages and more public announcements.
We are told loading procedures will also be changing. Supervisors will be reviewing loading procedures with staff ahead of time and they will be in close communication with captains throughout the evening.
Finally, WSF says there will be more Washington State Patrol and U.S. Coast Guard personnel on hand for increased security.
The WSF system has come under renewed criticisms this summer after a raft of problems including lengthy delays, a number cancellations, a disabled ferry mid-run, as well as the recent overloading of a ferry.