Ambergris Caye is reached by water taxi from Belize City (about 75 minutes) or by domestic flight to San Pedro's John Greif II Airport (about 20 minutes). Maya Island Air and Tropic Air both run multiple daily flights from Belize City's municipal airport (not the international airport — take a taxi or bus from the international terminal to the municipal one). Flights are small prop planes with a luggage weight limit.
Water taxis leave from the Marine Terminal in downtown Belize City; the crossing takes about 75 minutes in good conditions and can be rough. The fare is around USD 20 one way. For those arriving on international flights, the combination of international arrival, taxi to marine terminal, and water taxi journey takes at least three to four hours, so the short flight is often worth the extra cost.