Yes, travel insurance is worth having for a resort stay on this island in Fiji's Mamanuca group, and the honest reason has more to do with the surrounding waters and cyclone exposure than the island's own comfortable setting. A resort island can make it easy to forget how remote the wider Mamanucas actually sit, off the coast near Nadi, Fiji's main international gateway and the usual arrival point for almost every visitor to this island group.
Local medical facilities on a small Mamanuca island are limited to basic first aid at most, and anything serious typically means transfer first by boat or seaplane to Nadi or Suva on the Fiji mainland, with further specialist treatment often meaning onward evacuation to Auckland or a major Australian city given regional referral patterns across the South Pacific. Confirm your policy explicitly covers inter-island and international medical evacuation, since that multi-leg transfer, not treatment on the resort island itself, is the part most likely to involve real cost and coordination.
Diving and snorkeling on the reefs around the Mamanucas are genuine draws for most visitors, and both carry risk that a generic travel policy sometimes underinsures with depth caps or activity exclusions. Cyclone season, roughly November through April, adds a separate risk layer - storms can disrupt inter-island boat transfers and force evacuation of their own, so confirm your policy names both diving and cyclone-related trip disruption specifically, and check how it treats a resort stay cut short by an approaching storm.
Keep any resort clinic paperwork, dive-operator incident reports, and receipts for emergency transport if you need to file a claim, since documentation from a small offshore island is easy to lose track of. Check whether your existing health cover extends abroad and to this part of the South Pacific before relying on it, and confirm your policy's claims-reporting timeline before you travel rather than after something happens.