Grenada Island has numerous car-rental agencies. Most offer jeeps/SUVs (from around US$65/US$80 per day), and some have regular cars (from US$55).
Taxi fares on Grenada are regulated by the government, although you can sometimes negotiate a bit with the drivers. From the airport to Grand Anse or Lance aux Épines costs EC$40; to St George’s EC$50. From central St George’s it costs EC$40 to Grand Anse or Morne Rouge and EC$50 to Lance aux Épines. A taxi from the Lagoon to the Esplanade will set you back a hefty EC$25.
Otherwise, taxis charge around EC$65 per hour, whether driving or waiting.
Buses run all over the island on set routes, most of which originate at the central bus station in St George's.
With the exception of the St George's–Grand Anse route, which runs until around 9pm, buses generally run from around 7am to 7pm. Services start to thin out after 6pm, so start your return journey early enough to avoid getting stuck. Buses on all routes run infrequently, if at all, on Sundays.
Bus trips are economical with fares beginning at EC$2.50 and going up to around EC$8 for a cross-island journey.