Is Brian's Boat Works & Marina in GTA 6?
Confirmed Yes. Rockstar has shown or named this place.
Brian Heder’s boat yard. Rockstar’s bio says Brian is “still moving product through his boat yard with his third wife, Lori”. The yard’s sign is legible in Trailer 2, and the Launch Trailer opens on it (0:04): dry-stack boat racks with BRIAN’S MARINA across the roof and a red “Rent A Rack” sign. It is Brian’s business, not one Rockstar says the player can buy. See also the company entry and Brian Heder.
Sourced from official Rockstar material, news coverage and fan identification of models carried over from earlier Grand Theft Auto games. Every entry is labelled by how sure we are — anything not confirmed for GTA VI says so. See all properties.