The strange and impressively large ocean sunfishes have traditionally been considered to be solitary giants, drifting passively in ocean currents. Tagging studies have revealed the opposite – sunfish are active epipelagic hunters, diving deep for their meals. However, the epipelagic is not the only habitat these giants utelise. Seasonally, bump-head sunfish Mola alexandrini are seen on the shallow coral reefs (<40 m) off Nusa Penida near Bali, Indonesia, where they seek cleaner-fish interactions. The increasing tourist dive pressure on the sunfishes is of growing concern, however a paucity of understanding of this seasonal phenomenon prevents a meaningful impact assessment. In this study we examine the sunfish seasonality off Nusa Penida, the potential importance to the sunfish of the relatively limited Nusa Penida reef systems, as well as if the Nusa Penida Marine Protected Area offers a meaningful framework for regulating sunfish tourism dive pressure. We achieved this by investigating sunfish movements off Nusa Penida through application of towed SPLASH tags, and by estimating sunfish encounter rates at different reef sections based on > 4,000 tourist dives. The results indicate the biggest concern from the sunfish dive tourism may not be the sunfish, but rather the cleaner-fish habitat; the coral reefs.