A trip built around a private airstrip like the one on Fregate Island depends entirely on small aircraft actually operating on schedule, which is precisely why travel insurance matters here more than the island's setting might suggest. Fregate sits well outside the main Seychelles hub of Mahe, and access is by light aircraft alone; there is no ferry alternative and no scheduled commercial service beyond the charter flights that serve the island.
Fregate's own facilities handle only the most routine issues, so anything serious means evacuation off the island itself, typically to Mahe, home to Victoria and the main regional hospital for the Seychelles. Confirm your policy explicitly covers medical evacuation by air from a remote island airstrip, since that transfer, not treatment on Fregate, is the part most likely to involve real cost and coordination.
Weather and light-aircraft scheduling are the practical risk here: a single delayed or cancelled charter flight can strand a visitor on the island or on Mahe for an extra day, and the Seychelles' cyclone-adjacent storm season, roughly November through April, occasionally disrupts inter-island flights outright. Check that your policy covers trip-delay and missed-connection costs tied to charter or light-aircraft transfers specifically, since general airline-delay wording does not always extend to this kind of service, and a single missed connection here can mean an extra night's accommodation you did not plan for.
Keep any charter-operator confirmation or cancellation notice, clinic paperwork from Fregate or Mahe, and receipts for unplanned accommodation if a flight is disrupted. Many policies require prompt notice before major expenses like an air evacuation are incurred, so check the claims process in your policy wording well before you travel rather than after something goes wrong on an island this remote, since arranging documentation retroactively from Fregate is far harder than gathering it as you go.