Revākhaṇḍa ascribed to the Vāyupurāṇa (RKV) 19.41

19.41

vārāhamīśānavaro 'pyato 'sau rūpaṃ samāsthāya jagadvidhātā /
naṣṭe triloke 'rṇavatoyamagne vimārgitoyaughamaye 'ntarātmā //

Then, assuming the form of a boar, this best of lords, the creator of the universe,
the inner soul, when the three worlds were lost and immersed in ocean waters, searched through that expanse of waters.