Marine iguanas (Amblyrhynchus cristatus) are large reptiles found exclusively in the Galápagos Islands, hence them often being referred to as Galápagos Iguanas. They are the only lizard species capable of foraging in the ocean, utilising their robust bodies and  dark, often black colouration, that helps them absorb heat after swimming in the cold ocean. Males are generally larger, reaching up to 1.5 meters (5 feet) in length, while females are smaller.

These iguanas are herbivorous, primarily feeding on algae. They have special adaptations such as flattened tails for swimming and strong, sharp claws to help them cling to rocks in strong currents. They are often seen basking in the sun on rocky shores to regulate their body temperature after feeding in the chilly waters, which is a not an uncommon photo opportunity for travellers, and they are social animals that often dwell in large colonies.

Expedition guided excursions will be led by knowledgeable and local naturalists who provide insights into the behavior and ecology of the iguanas and their unique environment. 

The Galápagos Islands are a UNESCO World Heritage site, and marine iguanas are protected under Ecuadorian law. The Galápagos National Park and Marine Reserve ensure the conservation of their habitats.  Ongoing research and monitoring efforts help understand the impacts of climate change and human activities on marine iguana populations. Conservation programs focus on habitat protection and invasive species control.