From I-5 (North or South)
Take the West Seattle Bridge/Columbian Way exit (#163).
Follow the West Seattle Bridge signs.
Take the Harbor Island/11th Avenue SW exit.
Take the middle lane to the stop light and make a hard left, looping under the bridge.
Travel ¼ mile and turn right into the Harbor Marina Corporate Center (Klickitat Way).
Tideworks' office is the first building on the left.

From Highway 99 (Downtown Seattle)
Travel south on Highway 99 from downtown Seattle.
Take the Harbor Island exit (exit to Spokane Street).
Take the middle lane to the stop light and make a hard left, looping under the bridge.
Travel ¼ mile and turn right into the Harbor Marina Corporate Center (Klickitat Way).
Tideworks' office is the first building on the left.