Batu Mandi is a boat-access dive site off Bangka in North Sulawesi with a shallow coral start and a gradual profile that leads into pinnacles and a wall. It works well for diving and snorkeling on warm-water boat days, with planning centered on operator timing, steady buoyancy, and mild-to-medium current rather than a hard entry. Expect reef fish, nudibranchs, shrimps, crabs, pygmy seahorses, cuttlefish, and frogfish in the mix.