Peñas Blancas Safari Boat Tour in Arenal. Experience the Costa Rican rainforest by boat! On this full-day tour in Arenal, observe Costa Rican wildlife in its natural habitat as you cruise down the Peñas Blancas River with an expert guide. If you're up for adventure, this is the perfect tour for you! River safari tour on Peñas Blancas River in Arenal, Costa Rica. Expert local guide will take you through the rainforest by boat. See Costa Rican wildlife like sloths, monkeys, crocodiles and birds in their natural habitats. Complimentary hotel pickup and drop-off. Book Now and Save 6%: Peñas Blancas Safari Boat Tour in Arenal.