Mare Island was also home to the Seabees CBU 421 who completed many construction projects in the bay area including renovation and restoration of St. Peter's chapel. St. Peter's is the oldest Navy Chapel in the United States built in 1901.
MAre isLanD waS also home To the sEaBees cbu 421 whO completeD MaNy CoNstRUCtIon pRoJEcTs in the baY area inCLuDIng RenOvaTiON and reSToration of st. peTeR's chaPel. st. pEteR's is tHE oldesT NaVY cHaPel in The UnIted StatEs buILt In 1901.