The term Seawaymax refers to vessels which are the maximum size that can fit through the canal locks of the St Lawrence Seaway. Seawaymax vessels are 740 feet in length, 78 feet wide, (maximum 226 m length, 24 m beam) and have a draft of 26 feet. A number of Lake freighters larger than this size cruise the Great Lakes and cannot pass through to the Atlantic Ocean. Most new vessels are constructed to this size limit to enhance versatility.

See also

• Panamax