One of the boats had been set afire.afirea‧fire /əˈfaɪə $ əˈfaɪr/ adjective, adverb [not before noun] literary 
One of the boats had been set afire.
EXAMPLES FROM OTHER DICTIONARIES
- The oil tanker was afire.
COLLOCATIONS FROM THE ENTRY One of the boats had been set afire.
burning SYN ablaze: One of the boats had been set afire. One of the boats had been set afire.