The S23 is a bay boat by Lure Predator due to appear in Grand Theft Auto VI, spotted docked at a jetty with Jason and Lucia and cruising a Vice City canal in the second trailer, plus in Leonida Keys screenshots and a postcard. Its flats-style design appears to draw on several Contender boats, with a rear section resembling the Key West 188 BR.
Vehicle data via GTA Wiki (Fandom), CC BY-SA 3.0.