IPA: //ˈsiːˌwɜːrði//
KK: /ˈsiːˌwɜːrði/
Suitable and safe for traveling on the sea.
The old boat was finally repaired and deemed seaworthy for the journey.
Seaworthy is formed from "sea" (from Old English "sǣ", meaning the ocean or large body of saltwater) and "worthy" (from Old English "weorþig", meaning having worth or value). The word "seaworthy" describes a vessel that is fit or suitable for sailing on the sea.
Think of a ship being 'fit for the sea' — 'sea' refers to the ocean, and 'worthy' means having value or being suitable.