Each Engineer Special Brigade (2nd, 3rd and 4th) had a Engineer Boat Maintenance Battalion. These specialized groups consisted of five units: three Engineer Maintenance Companies, one Engineer Heavy Equipment Shop Company, and one Engineer Parts Supply Platoon.
One member of this unit trained at Camp Gordon Johnston. He was interviewed by the Library of Congress, which can be viewed here. LeRoy Joseph Meyers Collection | Library of Congress (loc.gov)
When we learn more about this 564th Engineer Boat Maintenance Battalion we will add it here.