Please keep in mind that cell service is spotty on the island if you have Verizon or AT&T, but T-Mobile is usually pretty good. I recommend downloading offline maps to get around.

Plan to get to the ferry terminal AT LEAST 45 minutes before your scheduled ferry time. The Anacortes Ferry Terminal is 90 minutes from Seattle with no traffic. We recommend leaving Seattle 2.5-3 hours before your sailing time. Ferries load before the scheduled departure time. If you arrive later than 30 minutes before, you will forfeit your reservation and will get charged the no-show fee. Once at the ferry terminal in Anacortes, you will drive up to the ferry booth, tell them your destination (Orcas Island), reservation name and time and purchase your tickets. You'll then drive up to a second booth where you will present your receipt and be directed to a holding line.

https://docs.google.com/document/d/1pAo6792jjY9u4rV8_AzvOO_yqyxy493yURzyY0850X0/edit?usp=sharing