Getting around Guinea-Bissau requires flexibility and low expectations. There is no rail network, domestic flights are rare, and the road system is poor.
Bush taxis are the main form of transport between towns. They are shared minibuses or sept-places (seven-seat Peugeots) that leave when full. The main routes from Bissau to Bafata and the Senegalese border are served regularly. Elsewhere, waits can be long.
Roads are paved between Bissau and a few major towns, but much of the country's road network is unpaved. In the rainy season (June to October), many roads become impassable -- even the paved ones can be rough. If you are driving, a 4x4 is essential outside Bissau.
Taxis operate within Bissau. They are cheap and identifiable by their blue color. Agree on a fare before getting in.
Boats are the only way to reach the Bijagos Islands. A weekly ferry and occasional fast boats depart from Bissau port. Within the archipelago, motorized canoes are the standard transport between islands.
Car hire is possible in Bissau but expensive and rarely worth it unless you are an experienced West African driver. Hiring a car with a driver is a better option for exploring beyond the capital.
There is no Uber or ride-hailing service. Distances are short -- the whole country is only about 350 kilometers across -- but travel times are long relative to distance because of road conditions.