A vessel is constructed with a steel hull and an aluminum superstructure. Which statement is TRUE?

Correct Answer: Option B — The aluminum structure is usually attached to a steel coaming by a method that insulates the two metals.

Aluminum superstructures joined to steel hulls require specialized insulation methods, such as explosive-bonded bimetallic transition joints, to prevent severe galvanic corrosion caused by direct contact between dissimilar metals in a marine electrolyte environment.