The RAW for the Oceans collection by the musician and the Dutch fashion brand has been revisited for Autumn Winter 2015, and carries the strap line: "Turning the tide on ocean plastic pollution".
The garments in the collection are all created using fabrics developed in collaboration with textile company Bionic Yarn and environmental group Parley for the Oceans – an initiative that encourages creatives to repurpose ocean waste and raise awareness of the growing issue.
Ocean plastic is broken down and woven with other materials to create the fabrics.
Ocean plastic is this year's breakthrough material. It has also been used by Adidas to produce a range of trainers, while a young designer has created a machine to harvest tonnes of the waste material from the sea.
London department store Selfridges is currently hosting an exhibition about ocean plastic that includes a series of objects crafted from the material by Studio Swine.
Related content: see more stories about design using ocean plastic
Parley for the Oceans has removed and repurposed roughly 700,000 PET plastic bottles from the sea for each RAW for the Oceans collection so far.
Williams' latest range, already available in G-Star stores and online, includes jeans and denim jackets, as well as T-shirts and sweatshirts.
The statement garment is a hooded jacket called the Occotis HDD Bomber. Covering most of the face when done up, the jacket is designed to look like a cross between a submarine escape suit and a military garment.
"The starting point of the RAW for the Oceans Autumn Winter 2015 collection's design came from a sketch drawn by Pharrell Williams of a face-covering hooded jacket," said G-Star in a statement.
A men's pea coat in raw black denim and a Breton stripe pattern using the initiative's octopus mascot follow the nautical theme.
The jeans and jackets are distressed and patched, and a chalky white paint treatment was given to the women's Occo Skinny jeans and shorts.
G-Star RAW's other collaborators include designer Marc Newson – who celebrated 10 years working with the brand last year – and architecture firm OMA, which designed its headquarters in Amsterdam. G-Star recently teamed up with Swiss furniture brand Vitra to update a range of 1940s designs by Jean Prouvé for use in modern offices.
When Dezeen spoke to the brand's creative director Shubhankar Ray earlier this year, he said that other design brands operate in an "insider world" and are failing to connect with young consumers.