Coast sits next to 4 phonetic neighbors — Cole, Colt, and Chase are the closest matches by sound. Most share Coast's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"land bordering the sea"
"tournament fighter"
"salvation of God"
"river (from Celtic afon)"
"just, righteous, equitable"
"brave, bold"
"roof maker"
"Moorish, dark-skinned"
"bright"
"bent river or stream"
"faithful, loyal, trustworthy"
"brave in battle"
"sacred song, hymn"
"young warrior, free man"
"cross"
"carrier, one who bears"
"victory of the people"
"small sheltered coastal bay"
"watchful, vigilant (via Casey)"
"son of the prince/lord"
"wine and grain"
Similar sound: These names share phonetic patterns with Coast — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Old French origins, giving them the same cultural heritage as Coast.
Rhythm: Coast is a 1-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.