You crossed a continent (or an ocean) for the cruise. The Pacific Northwest has more to show you. Four extensions scoped specifically for cruise passengers — one to two nights, all reachable from Seattle without a complicated reroute.
Victoria, BC (1 night)
Two-hour Victoria Clipper passenger ferry from downtown Seattle. Passport required.
The Inner Harbour, the Empress Hotel for afternoon tea, and Butchart Gardens 30 minutes north — peak bloom in June through September. Walkable downtown, no rental needed. The cleanest one-night extension if you're already in Seattle and have a valid passport.
San Juan Islands (1–2 nights)
Anacortes ferry to Friday Harbor, ~3 hours total from Seattle including the drive north.
Orca whale-watching season runs June through September — resident pods feed in the Salish Sea on a near-daily schedule. Friday Harbor is the canonical base; Roche Harbor for a quieter splurge. Rent a car at Sea-Tac, drive up; cars on the ferry book out weeks ahead in summer.
Olympic National Park (2 nights)
Drive west via the Bainbridge ferry. UNESCO World Heritage Site.
Three completely different ecosystems in one park: the Hoh Rainforest (one of the wettest places in the lower 48), Hurricane Ridge (subalpine meadows, snow into July), and the Pacific coast at Rialto Beach. Most cruise passengers see Alaska's nature from a ship; Olympic is the version you walk through.
Mount Rainier National Park (1–2 nights)
Two-hour drive southeast from Seattle.
The mountain you saw on clear days from the cruise ship, up close. Glaciers, wildflower meadows in late July through August (Paradise is the peak), and lodge rooms at the historic Paradise Inn or National Park Inn. Easy add for fly-out passengers with a flexible flight.