Both are seven-day cruises, one aboard the Conte Max from 24 September and priced at US $2050pp, the other on the Duke of York from 22 October for $2200pp.

The trips are timed to coincide with the most productive monsoon winds and lunar currents that influence reef mantas’ movements and feeding habits, says LYM.

That can mean changeable weather, but it should be worth it if guests find themselves in the water with feeding aggregations of the big rays.

The Duke of York trip, guided by the Manta Trust’s Simon Hilbourne, will visit rarely visited reefs in Baa, Raa and Lhaviyani, while Conte Max will visit Baa as well as North Ari atolls, under the guidance of Tam Sawers.

Guests on both can contribute to the ever-expanding manta database.