The first Indian to cross seven important seas by swimming ____ ?

Explanation:

Bula Chaudhury, Indian swimmer best known for her long-distance swimming feats.

In 2005 she became the first woman to have swum across sea channels of five continents including the Strait of Gibraltar, the Tyrrhenian Sea, Cook Strait, Toroneos Gulf (Gulf of Kassandra) in Greece, the Catalina Channel off the California coast, and from Three Anchor Bay to Robben Island near Cape Town, South Africa.