deriv LSK ETT STT aSTA ALPH OLDHOMEPAGE NEWHOMEPAGE
The base **nau- नौॱ f "ship" is the only commonly used nounbase that ends in au औ.
Before vowel endings, it gets ecoyavAyAvaH —
/nau- + /Ge → nAv नाव् + e ए by ecoyavAyAvaH → !**nAve नावे
/nau- + /am → !**nAvam नावम्
/nau- + /au → !**nAvau नावौ
/nau- + /jas OR /zas OR /Gas OR /Gasi → !**nAvaH नावः
/nau- + /Am → !**nAvAm नावाम्
/nau- + /TA → !**nAvA नावा
The other noun endings are added directly —
/nau- + /su → !**naus नौस् JBJ
/nau- + /bhis → !**naubhis नौभिस्
/nau- + /bhyAm → !**naubhyAm नौभ्याम्
/nau- + /sup' → **nauSu नौषु, with /Satvam
(As a curiosity: /nau- appears to be the only base that gets all the endings in list svaujasamauTch... with no replacement.)
Even the /sambuddhi stays, because no rule deletes it:
/nau- + /sambuddhi → !**naus' नौस्ऽ JBJ
he gagana-nauH हे गगनॱनौः "hey sentient spaceship!"
This /nau- is the only common nounbase after which none of the noun endings is replaced by any rule.
But of course there will be changes when it becomes a neuter ifc —
bahunu taTam बहुनु तटम् "coast having many ships", with svamornapuMs... and hrasvonapuMs... and eca::igghrasv...