The Black Swan design grew out of the Bitterns, which complicates the usual class labels. Indian vessels in this lineage are often called modified Black Swans, while other sources describe them as modified Bitterns. Both labels reflect the same design history because the Black Swan itself was a development of the Bittern design. Each generation retained a proven hull concept while changing armament, machinery, or arrangement to meet a new requirement. That repeated refinement helps explain why the design was considered reliable.
Notable Point · 14:07-15:27
The Black Swan lineage begins with Bittern
The famous Black Swan sloops were evolutionary descendants of the Bittern design, including vessels often described as modified Black Swans.