Ensign Gina Caylor is dwarfed by 10,000 tons of steel in a dry dock at Mare Island in Vallejo. The USCGC Polar Star is the Coast Guard's only operational heavy icebreaker. (Adam Grossberg/KQED)

Workers hydroblast the hull of Polar Star, preparing for repainting during three months of repairs. (Adam Grossberg/KQED)

About 150 workers worked on Polar Star at Mare Island Dry Dock Company. That included removing and refurbishing the ship's three propellers, each 18 feet across. (Adam Grossberg/KQED)

Commissioned in 1976, Polar Star is already 10 years past its intended operational life. (Adam Grossberg/KQED)

The dry docks, recently put back into service, are a legacy from when Mare Island was a major naval shipyard and submarine base. (Adam Grossberg/KQED)