Designed by W. C. Nickum & Sons, and financed by $23 million in state bonds and federal funds, the four ferries of the Hyak class were enlarged versions of the Evergreen State class, built by Puget Sound Bridge and Drydock Company in the mid-1950s. The new ferries were 382 feet long, carried 2,067 passengers and 160 automobiles, and had more than three times the horsepower of the Evergreen State class. At a service speed of 20 knots, the new ferries were 43 percent faster.
Originally, the state planned to retire several older ferries once the superferries were in service, but an economic boom at the time necessitated the retention of some of them.
The Hyak went into service on the Seattle-Bremerton run during July 1967. The trip took 45 minutes, compared to an hour and five minutes on older ferries.