Sail the quieter Lan Ha side of Ha Long Bay on a spacious day cruiser with a certified English-speaking guide. Begin at Cai Beo Floating Village—one of Vietnam’s oldest—then swim & snorkel at Ba Trai Dao/Van Boi and kayak the Dark & Bright Caves in this UNESCO seascape. In the afternoon, step ashore at Viet Hai ancient village in Cat Ba National Park for a gentle cycling loop through rice fields and village lanes, and try a natural fish-foot massage in the clear stream. Enjoy a traditional Vietnamese lunch on board; all kayak/snorkel gear included, hotel pickup/drop-off in Cat Ba town, and a sunset tea & fruit chill on deck. Occasional wildlife sightings (e.g., monkeys) are possible; langur not guaranteed. A complete, well-paced one-day experience for nature lovers who want both activity and relaxation.