The Nauticat 331 is a newer and slightly larger version of the Nauticat 33, built by the same Finnish company, Siltala Yachts. It has a length of 10.4 m (34'1") compared to the Nauticat 33's 10.1 m (33'2"). It also has a deeper fin keel with a draft of 1.48 m (4'10") compared to the Nauticat 33's 1.4 m (4'7") or 1.8 m (5'11"). The Nauticat 331 has a similar layout and design as the Nauticat 33, but with some modern updates and improvements. The Nauticat 331 was built between 1999 and 2018, while the Nauticat 33 was built between 1966 and 1994.