Petty Officer 3rd Class Nick Bean, electrician's mate assigned to Aids to Navigation Team San Francisco, measures the acid density using a refractometer during his maintenance checks for Alcatraz Lighthouse. ANT San Francisco's trained technicians visit the lighthouse on a quarterly basis to perform maintenance procedures to ensure the light is in top working condition. Coast Guard photo by Petty Officer 2nd Class Loumania Stewart

---

Size: 2048px × 1365px
Photo credit: © AB Forces News Collection / Alamy / Afripics
License: Licensed
Model Released: No

Keywords: aids, alcatraz, ant, coast, francisco, guard, lighthouse, navigation, san