At the Border
The Canawaima Ferry to Suriname (one-way/round-trip per person G$3500/4500, 30 minutes, 10:30am daily) leaves from Moleson Creek and crosses the Corentyne River to the Suriname border at South Drain, 45 minutes south of Nieuw Nickerie. Get to the ferry no later than one hour before departure to stamp passports and go through customs control. There are no border-crossing fees and immigration remains open to coincide with boat arrivals and departures.
Most nationalities will need a Suriname Tourist Card or visa from a Surinamese consulate or embassy to enter Suriname. These cannot be obtained on the border, so plan in advance; this is a Surinamese Embassy in Georgetown.
Minibuses to Nieuw Nickerie and Paramaribo meet the ferry on the Suriname side. It's best to change your Guyanese currency before leaving Guyana in case no one's buying across the river. Make sure you know your rates before you make the exchange.
Note that Suriname is an hour ahead of Guyana.