Thieves broke into an RNLI lifeboat station in Norfolk overnight and stole essential rescue gear.
The Happisburgh crew arrived on Saturday to find radios, night-vision binoculars, and global positioning system (GPS) equipment missing.
Crew spokesman Phil Smith said he believed the thieves knew what they were looking for and did not care that they have put lives at risk.
It is thought the thieves might offer the goods for second-hand sale.
Anyone offered the items, or who has information about the break-in is asked to ring Norfolk Police or Crimestoppers.