Advantages of Steel Boat Construction:
Strength. Steel is incredibly strong. It has excellent abrasion and impact resistance. If strength is the primary consideration for a boat building material then steel would be a good choice.
Cost. It relatively inexpensive as compared to aluminum.
Disadvantages of Steel Boat Construction:
Weight. Steel is heavy. If considering building a boat less then 40 feet in length, the plate thickness needed to build with would make steel excessively heavy. A steel hull with aluminum superstructure would be a good option.
Rust. Unless extreme attention is used during the finishing process, steel will undoubtedly begin to rust. Excessive rusting is unsightly and weakens the material.