The world’s largest whale shark and manta aggregation in Mexico’s Caribbean

Experience the world’s largest known aggregation of whale sharks and manta rays feeding in the clear, warm waters just 30–45 minutes from Isla Mujeres, off the northeastern tip of Mexico’s Yucatán Peninsula. This extraordinary encounter offers the chance to snorkel alongside the world’s largest fish and, if conditions allow, the world’s largest ray, while contributing to a global citizen science effort advancing our understanding of migratory routes, residency, and population sizes.

Picture a swirling tapestry of open-mouthed, white-spotted whale sharks and graceful, jet-black manta rays moving through turquoise waters. You will be guided by Dr. Rachel Graham, Founder and Executive Director of MarAlliance, a globally recognized expert who has spent more than 20 years leading pioneering research on whale sharks and manta rays. She was the first person in the Western Hemisphere to complete a PhD on whale sharks and has published extensively on both species, while also helping to shape responsible tourism practices in countries including Mexico.

Through her guidance, you will gain firsthand insight into the behavior, ecology, and conservation of these remarkable animals while actively supporting ongoing research.

This snorkeling-only experience is suitable for adults and for children aged 14 and older when accompanied by an adult.

From her early days growing up by the sea in Tunisia, Dr. Rachel Graham was drawn to research, conservation, and development across Latin America, Africa, and Micronesia. For over 30 years, she has worked with the private sector and organizations such as the United Nations, University of York, Smithsonian Institution, and Wildlife Conservation Society. In 2014, Rachel founded the international NGO MarAlliance to promote inclusive, grassroots science and marine conservation.

For over two decades, Rachel has lived in Belize and worked with fishers and partners in several countries to identify threats, research needs, and conservation opportunities for threatened marine wildlife and their critical habitats. Her work has driven megafauna research and conservation worldwide, and she actively serves on the IUCN Shark Specialist Group, co-founding several National Shark Advisory Committees to advance policy reform for elasmobranchs.

In recognition of her contributions, Rachel received the Whitley Fund for Nature Gold Award in 2011 and the Pew Marine Fellowship in 2021 for her shark research and conservation work. Rachel holds a BSc in Zoology from Oxford, an MSc from Edinburgh, and a PhD from the University of York, UK. She is especially proud of her two sons, who share her passion for fishing and marine conservation.