Getting to Sherbro Island requires patience and some local knowledge. The most common route from Freetown involves a combination of road transport south to the coastal town of Mattru Jong or Gbondapi, followed by a boat crossing. The ferry service is irregular and the crossing time varies with conditions. Some visitors take a direct speedboat from Freetown, which takes several hours and can be expensive to charter.
There is an airstrip at Bonthe, and small charter flights operated by NGO or mining company aircraft occasionally make the run from Lungi — but scheduled civilian air service is unreliable to non-existent. Check locally in Freetown about the current situation before committing to any plan. Whatever route you choose, allow more time than you expect the journey to take.