Union Island is reached by a combination of air and ferry. The island has its own small airstrip, Union Island Airport (UNI), which handles regional turboprop flights from Kingstown (St Vincent), Grenada, and Barbados operated by SVG Air and Mustique Airways. Flights take between 20 and 45 minutes depending on origin.
The alternative is the ferry from St Vincent — the Jaden Sun and similar vessels run a multi-stop route through the Grenadines, calling at Bequia, Canouan, and Mayreau before reaching Union Island. The journey from Kingstown takes around 3–4 hours in good conditions and costs a fraction of the airfare. Day-trippers can also reach Union Island on water taxis from Canouan and Carriacou (Grenada) if you are already in the southern Grenadines.
Yachties passing through the Grenadines use Clifton Harbour as the official port of entry for St Vincent and the Grenadines when coming from the south.