Matsya Purana — Description of Gomedaka and Puṣkara Dvīpas; the Lokāloka Boundary; Ocean Tide...
एवं द्वीपसमुद्राणां वृद्धिर्ज्ञेया परस्परम् अपां चैव समुद्रेकात् समुद्र इति संज्ञितः //
evaṃ dvīpasamudrāṇāṃ vṛddhirjñeyā parasparam apāṃ caiva samudrekāt samudra iti saṃjñitaḥ //
Thus, the successive expansion of the continents and the oceans is to be understood as increasing in relation to one another; and because it is a single continuous body of waters, it is designated by the name “ocean.”
This verse is not directly about Pralaya; it clarifies cosmographic structure—how continents and oceans are described as mutually increasing, with the waters regarded as one continuous “ocean.”
Indirectly, it supports the Purāṇic ideal of informed rulership and household learning: understanding the world-order (cosmography) is part of traditional śāstric knowledge that grounds dharma, pilgrimage geography, and calendrical/ritual orientation.
No explicit Vāstu rule is stated, but the idea of ordered spatial arrangement (dvīpa–samudra sequence) reflects the broader Purāṇic concern for cosmic order, which Vāstu and temple planning often mirror through concentric, proportionate layouts.