In 2004, the vessel was refit with a second vehicle deck, and in 2005 was refit with safety equipment to meet the requirements of the International Convention for the Safety of Life at Sea (SOLAS), allowing the Chelan to make international trips on the Anacortes–San Juan Islands–Sidney, British Columbia route.

As of April 2020[update] the Chelan is the only vessel in the Washington State Ferries fleet that meets SOLAS standards.

In 2004, she was refit, much like her sister ships to include a second vehicle deck along the outer bulkheads.

After changes in United States Coast Guard rules for international travel, the Chelan was upgraded in 2005 safety equipment to meet the requirements of the International Convention for the Safety of Life at Sea (SOLAS).

The safety equipment requirements of SOLAS limit the Chelan to 1,090 passengers when making international trips, as opposed to the 1,200 she can carry on domestic crossings.