Strictly speaking, when a ship has gone through 90 degrees of roll, where her decks are vertical. In such case a ship would probably capsize (roll completely over). Can be used to refer to extreme rolls, even if less than 90 degrees.
Xa inqanawe ihambe amaqondo angama-90 omjikelo, apho imigangatho yayo ithe nkqo. Kwimeko enjalo inqanawe ingaphethuka (iqengqeleke ngokupheleleyo). Oku kungasetyenziwa xa kubhekiswa kuqengqeleko olugqithisileyo, akukhathaliseki nokuba kungaphantsi kwamaqondo angama-90.