You can take the ferry from Mukilteo and spend the day over to the beautiful Whidbey island. The ferry route is from Mukilteo to Clinton. It's a quick trip with ocean views. You can take your car for a small fee (around $20 for your car and 2 passengers). There are great cafes, coffee, and gift shops in Langley, WA. It is about a 15 min drive once you're off the ferry in Clinton. We recommend stopping by the Whidbey Island Pie shop! If water views and state parks are more your thing, recommend driving up to Ebey's Landing at Ebey's State Park! It's about a 42 min drive from the ferry landing. https://whidbeycamanoislands.com/things-to-do/
There is a lighthouse and waterfront public park right down the road from our wedding venue. It's a historical landmark that is free for all ages to enjoy! There is a great restaurant called Ivar's that you can walk up to get fish/chips to-go to enjoy while at the park. https://www.ivars.com/mukilteo-landing