The official currency of Dominica is the Eastern Caribbean dollar (EC$) , although US dollars are widely accepted and used to quote hotel and service rates. The EC$ is divided into 100 cents. Bills come in denominations of 5, 10, 20, 50 and 100 EC dollars; coins in 1, 2, 5, 10 and 25 cents. At the time of writing, the rate of exchange was EC$2.70 to US$1.

Most Roseau banks have ATMs dispensing local currency. Tellers here will also change money for transactions (Mon-Thurs 8am-3pm, Fri 8am-5pm). When paying for goods with US dollars in cash, the rate is usually lower, at $EC2.60/US$1.

Even though Dominica is poor by Caribbean standards, it's not the cheapest place to visit. Additional costs for guides and activities have a way of increasing your bill, as do incidentals like the US$15 departure tax levied at the airport when you leave. A whale-watching outing will be your biggest one-time expenditure, at US$50/four-hour trip; diving is only slightly less expensive, at US$45/single-tank dive.

At the bottom of the scale, you could manage on a daily budget of US$30, if you split the cost of a fan-only, shared-bathroom double in a Roseau guesthouse, travel by bus, hike without a guide, and skip diving and whale-watching altogether. A budget of US$70/day will allow you to stay in a rainforest guesthouse and hire a guide.