The Coast Guard has awarded Marinette Marine a $21.9 million contract for 10 additional Response Boat-Medium (RB-M) craft slated to begin delivery in the fourth quarter of 2012.

So far the Coast Guard has contracted for 115 of a potential planned buy of 250 of the 45-foot RB-M craft, which are used to meet mission requirements for ports, waterways and coastal security, search and rescue, drug interdiction and migrant interdiction. Coast Guard crews also use the boats to support marine safety, aids to navigation, marine environmental protection, and defense readiness. The potential value of the RB-M contract if all the boats are built is $600 million.

Marinette Marine, which is a division of Italy’s Fincantieri, will build half the boats at its facility in Green Bay, Wis. The company’s teaming partner, Kvichak Marine Industries of Seattle, will build the rest of the boats at its Kent, Wash., facility.