A much better bet for hitting the beach near Retalhuleu  is El Tulate, about an hour from town. The beach isn’t as clean as the one at Tilapa, but there’s at least one serviceable hotel here.
The rooms at Playa Paraíso (tel. 5988-4084, $40 d) have big, cushy beds, ceiling fan, thatch roof, and a porch with bamboo furniture. There are two swimming pools and a restaurant.
To get to the beaches, you’ll have to cross the Canal de Chiquimulilla. The cheapest crossing, if you’re coming to Playa Paraío, is found by turning left when the main road dead-ends at the canal and continuing for 100 meters. It should cost about $0.25 to make the crossing. Local ferry boat operators will try to charge you $2 to cross closer to the end of the main road.