Lipari, Vulcano and Stromboli combine serious volcanic diving with one of the Mediterranean's most dramatic island journeys. Base on Lipari for the broadest ferry links, restaurants, archaeology and established dive centers. Cross to Vulcano for sponge-coated walls, sulfur-tinted sand and the photogenic grotto at Scoglio del Quaglietto. Treat Stromboli as a dedicated expedition: its black-water backdrop, Strombolicchio and Sciara del Fuoco are compelling, but sailing conditions and volcanic access rules can change the plan. Underwater highlights include white pumice at Punta Castagna, red gorgonians, grouper, nudibranchs, lava gullies and the protected archaeological context at Secca di Capistello. Late May to June and September to early October offer the best overall balance of warm water, workable boats and more comfortable topside weather. July and August are warmest but busiest and hottest. This is primarily a local-operator, day-boat destination, not a liveaboard trip.