To get to Lazarus Island and the Southern Islands, it's a 30-minute ferry ride from Marina South Pier. There's an MRT stop right at the marina, on the red North-South Line. There are two ferry companies (Marina South Ferries) and (Singapore Island Cruise), both with similar timetables and ticket prices. Book in advance to guarantee a spot at the weekend, or just turn up and book a ticket on the day of travel.