Coast
Shore
noun, の adjective
The run alongside coast basically just describes the coast.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
今度の日曜日にヨットで沿岸を一緒に帆走しないかって彼に誘われたんだ。
He asked me to sail along the coast in his yacht with him this Sunday.