Waisalima Beach is excellent for snorkeling and diving due to its proximity to Kadavu's renowned reef systems. The beach's eastern location provides access to diverse marine environments, including coral gardens, reef walls, and channels teeming with tropical fish, rays, and sharks. Snorkeling is possible from shore in many areas, though local guidance is valuable for finding the best spots and understanding currents. Diving typically requires boat access to premier sites, which local operators or accommodations can arrange. Water clarity is generally excellent, especially during dry season. The remote location means uncrowded reefs in pristine condition, offering couples and serious divers memorable underwater experiences.

The best time to visit Waisalima Beach is during Fiji's dry season from May to October, when weather is most stable, seas calmer, and underwater visibility optimal for diving and snorkeling. These months offer sunshine, lower humidity, and minimal rainfall, with visibility often exceeding 25 meters. The period also experiences fewer crowds—already minimal on remote eastern Kadavu. Water temperatures remain warm year-round at 25-28°C. April and November provide shoulder-season advantages with good conditions and even greater solitude. While the beach is accessible year-round, the wet season from December to March can bring reduced visibility, rougher seas, and afternoon storms, though committed divers still find value.